Electropneumatic conversion mechanism and electropneumatic conversion structure

Abstract

To reduce sizes of an electropneumatic conversion mechanism and an electropneumatic conversion structure having the same.SOLUTION: An electropneumatic conversion mechanism 10 converts an electrical signal to an air pressure signal. The electropneumatic conversion mechanism 10 comprises a flow passage member 20 having: a first air flow passage R1 having a first end E1 to which air is supplied, and a second end E2 from which the air is discharged; and a second air flow passage R2 connected to the middle of the first air flow passage R1, and taking out a change in air pressure in the first air flow passage R1 as the air pressure signal. The electropneumatic conversion mechanism 10 further comprises a variable throttle mechanism 30 for changing the air pressure by changing a discharge amount of air which is discharged from the second end E2 of the first air flow passage R1. The variable throttle mechanism 30 comprises a diaphragm 31 for changing the discharge amount of the air by being deformed, and a piezoelectric element 32 formed above the diaphragm 31 and changing the diaphragm by being deformed by the electrical signal.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an electro-pneumatic conversion mechanism and an electro-pneumatic conversion structure that convert an electrical signal into a pneumatic signal.

Background Art

[0002] A nozzle flapper mechanism is used in an electro-pneumatic conversion mechanism that converts an electrical signal into a pneumatic signal. As disclosed in Patent Document 1, the nozzle flapper mechanism changes the nozzle back pressure, which is the pressure inside the nozzle, by displacing a flapper facing the nozzle based on an electrical signal. The change in the nozzle back pressure is taken out as a pneumatic signal.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As disclosed in Patent Document 1, in a conventionally used nozzle flapper mechanism, an excitation coil or the like for displacing the flapper is used. This excitation coil or the like has limitations in miniaturization, and the conventional nozzle flapper mechanism tends to become large.

[0005] The present invention has been made in view of the above points, and an object thereof is to miniaturize an electro-pneumatic conversion mechanism and an electro-pneumatic conversion structure including the same.

Means for Solving the Problems

[0006] To solve the above problems, the pneumatic conversion mechanism according to the present invention is a pneumatic conversion mechanism that converts an electric signal into a pneumatic signal, and includes a first air flow path having a first end to which air is supplied and a second end for discharging the air, and a second air flow path connected to an intermediate position of the first air flow path for extracting a change in air pressure in the first air flow path as a pneumatic signal. A flow path member including: a fixed throttle provided between the first end and the intermediate position of the first air flow path; and a variable throttle mechanism for changing the air pressure by changing the discharge amount of the air discharged from the second end of the first air flow path. The variable throttle mechanism includes a diaphragm that changes the discharge amount by deforming, and a piezoelectric element formed on the diaphragm that deforms the diaphragm by deforming in response to an electric signal.

[0007] The diaphragm may form the first air flow path at a position between the second end and the intermediate position, and change the cross-sectional area of the first air flow path by deforming, thereby changing the discharge amount.

[0008] The variable throttle mechanism may further include a support portion that supports the diaphragm in a state facing the second end, and the diaphragm changes the distance from the second end by deforming, thereby changing the discharge amount.

[0009] The support portion may be connected to at least both ends sandwiching the piezoelectric element of the diaphragm.

[0010] The support portion may be connected to at least both ends sandwiching the piezoelectric element of the diaphragm.

[0011] The diaphragm and the support portion may be integrally formed.

[0012] The flow path member and the variable throttle mechanism may be at least a part of MEMS (Micro Electro Mechanical Systems).

[0013] The pneumatic-electric conversion structure according to the present invention has a plurality of pneumatic-electric conversion mechanisms, each of which is the above-described pneumatic-electric conversion mechanism. The first air flow paths of each of the plurality of pneumatic-electric conversion mechanisms are connected in parallel to the air supply source, and the second air flow paths of each of the plurality of pneumatic-electric conversion mechanisms are connected in parallel to the output destination of the pneumatic signal.

Effects of the Invention

[0014] According to the present invention, the pneumatic-electric conversion mechanism and the pneumatic-electric conversion structure including the same are miniaturized.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0016] Hereinafter, an electropneumatic conversion mechanism according to an embodiment of the present invention and an electropneumatic conversion structure including a plurality of electropneumatic conversion mechanisms will be described with reference to the drawings.

[0017] <First Embodiment> As shown in FIGS. 1 and 2, the electropneumatic conversion mechanism 10 according to the first embodiment is used in the electropneumatic converter 1. The electropneumatic converter 1 includes, in addition to the electropneumatic conversion mechanism 10, a control circuit 70 and a pilot relay (pneumatic amplifier) 80. The control circuit 70 is configured to include a microcomputer or a logic circuit, etc. The control circuit 70 obtains the deviation between the set air pressure sent from the upper device U and the output air pressure to the actuator of the regulating valve V (such as a valve provided in the middle of the pipe), which is the control target. The output air pressure is measured by a sensor S provided in the middle of the path of the output air pressure. The control circuit 70 generates an electric signal corresponding to the obtained deviation as a control signal and outputs it to the electropneumatic conversion mechanism 10. The electropneumatic conversion mechanism 10 converts the control signal from the control circuit 70 into a pneumatic pressure signal using the air from the air supply source AS, and outputs the converted pneumatic pressure signal to the pilot relay 80. The pilot relay 80 amplifies the pneumatic pressure signal output from the electropneumatic conversion mechanism 10, and outputs the amplified pneumatic pressure signal as the output air pressure to the actuator of the regulating valve V. Then, the actuator operates by the output output air pressure, and the valve opening degree of the regulating valve V is operated.

[0018] The electropneumatic conversion mechanism 10 includes a flow path member 20 having a first air flow path R1 and a second air flow path R2 connected in the middle of the first air flow path R1, and a variable throttle mechanism 30 mounted on the flow path member 20.

[0019] As shown in FIGS. 1 to 3, the flow path member 20 includes a first member 21 serving as a base and a second member 22 fixed to the first member 21. The first member 21 is formed in a rectangular parallelepiped shape. The first member 21 has a groove 21A that opens on the upper surface to which the second member 22 is fixed. The second member 22 is formed in a plate shape and is fixed to the first member 21 so as to cover the groove 21A of the first member 21. By covering the groove 21A, the second member 22 forms a first air flow path R1, which is an air flow path for the air supplied from the air supply source AS, together with the inner surface of the groove 21A. A second air flow path R2, which is a through hole, is formed in the second member 22. The second air flow path R2 is connected to a predetermined intermediate position in the first air flow path R1.

[0020] The first air flow path R1 is formed linearly. The first air flow path R1 is an air flow path through which air from the air supply source AS flows, and includes a first end E1 (the left end in FIG. 1) to which the air is supplied and a second end E2 that discharges the air flowing into the first air flow path R1 from the first end E1 to the outside of the first air flow path R1. The flow path member 20 is configured as a nozzle having the second end E2 that discharges the air in the first air flow path R1 as a nozzle port.

[0021] The second air flow path R2 extends in a direction orthogonal to the direction in which the first air flow path R1 extends. A part of the air flowing in the first air flow path R1 flows into the second air flow path R2. The second air flow path R2 is connected to a pilot relay 80. The second air flow path R2 is configured to extract a change in the air pressure (also referred to as back pressure) in the first air flow path R1 as an air pressure signal and supply it to the pilot relay 80. The air pressure signal is supplied to the pilot relay 80, amplified, and then supplied to the control valve V.

[0022] The flow path member 20 also includes orifices 25 and 26 formed inside the groove 21A of the first member 21. The orifice 25 functions as a fixed throttle that causes a pressure loss by reducing the cross-sectional area of the first air flow path R1. The orifices 25 and 26 are composed of convex portions that protrude from the bottom of the groove 21A in the opening direction of the groove 21A, that is, toward the second member 22 side. The orifices 25 and 26 are arranged at intervals along the upstream and downstream directions of the first air flow path R1. Among the orifices 25 and 26, the orifice 26 is located on the downstream side. The orifice 25 is arranged between the first end E1 of the first air flow path R1 and an intermediate position where the second air flow path R2 of the first air flow path R1 is connected, and the orifice 26 is arranged between the intermediate position and the second end E2 of the first air flow path R1. Due to these arrangements, the second air flow path R2 is arranged between the orifices 25 and 26, and the air pressure in the space between the orifices 25 and 26 in the first air flow path R1 is taken out through the second air flow path R2.

[0023] A hole 22A is formed in a portion of the second member 22 that faces the orifice 26. A variable throttle mechanism 30 is arranged in the second member 22 so as to close the hole 22A. The variable throttle mechanism 30 constitutes a variable throttle that changes the air pressure in the first air flow path R1 by changing the cross-sectional area of the portion of the first air flow path R1 where the orifice 26 is formed and thereby changing the discharge amount of the air discharged from the second end E2 of the first air flow path R1.

[0024] The variable throttle mechanism 30 includes a diaphragm 31 that closes the hole 22A and faces the orifice 26, and a piezoelectric element 32 formed on the diaphragm 31. The entire outer peripheral end of the diaphragm 31 is connected to the second member 22, thereby closing the hole 22A. The diaphragm 31 is integrally formed with the second member 22. The piezoelectric element 32 is connected to the control circuit 70 and deforms by an electrical signal as the control signal from the control circuit 70. As shown by the dotted line in FIG. 2, the diaphragm 31 deforms so as to bulge toward the orifice 26 due to the deformation of the piezoelectric element 32. The diaphragm 31 deforms such that the central portion approaches the orifice 26 most closely. Due to the deformation of the diaphragm 31, the cross-sectional area of the portion of the first air flow path R1 where the orifice 26 is formed decreases.

[0025] When the cross-sectional area of the portion of the first air flow path R1 where the orifice 26 is formed decreases due to the deformation of the diaphragm 31, the discharge amount of the air discharged from the second end E2 of the first air flow path R1 decreases. For this reason, the air pressure (back pressure) between the orifice 25 in the first air flow path R1 and the diaphragm 31 and the orifice 26 increases. This increase in air pressure is taken out as an air pressure signal via the second air flow path R2 and output to the pilot relay 80. As a result, the electrical signal as the control signal from the control circuit 70 that deforms the diaphragm 31 is converted into an air pressure signal by the electropneumatic conversion mechanism 10.

[0026] In this embodiment, since the variable throttle mechanism 30 is constituted by the diaphragm 31 and the piezoelectric element 32 which are small and thin, the miniaturization of the electropneumatic conversion mechanism 10 is realized as compared with the case where a nozzle flapper mechanism constituted by relatively large components such as an excitation coil is adopted. Further, in this embodiment, since the diaphragm 31 constituting the variable throttle mechanism 30 is disposed on the first air flow path, the flapper is not disposed outside the flow path member 20 as in the conventional nozzle flapper mechanism, and the entire electropneumatic conversion mechanism 10 is miniaturized.

[0027] The electropneumatic conversion mechanism 10 may be formed, for example, as at least a part of MEMS (Micro Electro Mechanical Systems). At this time, the control circuit 70 may also be configured as MEMS together with the electropneumatic conversion mechanism 10. In this case, the electropneumatic conversion mechanism 10 may be regarded as also including the control circuit 70. As shown in FIG. 4, the control circuit 70 may be formed on a member constituting the electropneumatic conversion mechanism 10 together with a wiring L1 that connects the control circuit 70 and the piezoelectric element 32 and transmits a control signal. In the example of FIG. 4, the control circuit 70 is provided on the flow path member 20 (here, the second member 22). The wiring L1 is provided across the flow path member 20 and the diaphragm 31.

[0028] The electropneumatic conversion mechanism 10 can be formed by any MEMS manufacturing process such as bulk micromachining or surface micromachining. For example, the first member 21, the orifices 25 and 26 shown in FIG. 1 and the like are integrally formed by processing an SOI (Silicon On Insulator) wafer or the like by etching or the like. The second member 22 is integrally formed with the diaphragm 31 by processing an SOI wafer or the like by etching or the like. On the second member 22, a piezoelectric element 32, a control circuit 70, wirings connecting these, and the like are also formed by a film forming process or the like. Finally, by joining the first member 21 and the second member 22, the electropneumatic conversion mechanism 10 equipped with the control circuit 70 is formed. As shown in the cross-sectional view of FIG. 2, the electropneumatic conversion mechanism 10 is formed in a laminated structure and formed as one chip. Thereby, the electropneumatic conversion mechanism 10 is miniaturized. The manufacturing technology of MEMS is suitable for forming the diaphragm 31. Therefore, the electropneumatic conversion mechanism 10 adopting the diaphragm 31 can be easily miniaturized by the manufacturing technology of MEMS. According to the manufacturing technology of MEMS, the height of the first air flow path R1 can be set to several hundreds of μm or several mm, and the height of the first air flow path R1 when the diaphragm 31 is deformed can be set to 10 to 100 μm.

[0029] Conventional nozzle flapper mechanisms are manufactured by machining. However, the orifice holes of the fixed orifice, which are the main components, require fine machining on the order of 10 to 100 μm. Also, the movable range of the variable gap (the range in which the pneumatic conversion function is exhibited) formed by the flapper and the nozzle part is also on the order of 10 to 100 μm. Therefore, attention must be paid to the machining of its surface roughness and the like. Moreover, no matter how much attention is paid to the machining, the degree of variation in the final product is large, and adjustment work after assembly is essential. On the other hand, by forming the electro-pneumatic conversion mechanism 10 with MEMS, such adjustment work does not occur. Furthermore, mass production becomes possible on a silicon wafer or the like. As a result, the manufacturing cost of the electro-pneumatic conversion mechanism 10 as MEMS is reduced.

[0030] <Second Embodiment> The electro-pneumatic conversion mechanism 110 according to the second embodiment will be described centering on the points different from the electro-pneumatic conversion mechanism 10 according to the first embodiment. For elements having the same structure or function as those in the first embodiment in the second embodiment, the same reference numerals will be appropriately assigned, and the description thereof will follow the first embodiment. This also applies to the third embodiment and subsequent embodiments.

[0031] As shown in FIGS. 5 and 6, the flow path member 120 of the electro-pneumatic conversion mechanism 110 according to the present embodiment includes an orifice 125 instead of the orifice 25 of the first embodiment. The orifice 125 includes two convex portions 125A and 125B protruding from the inner surfaces on both sides of the groove 21A of the first member 21. The convex portions 125A and 125B are formed in a triangular prism shape. Such an orifice 125 of this shape can also be easily formed by MEMS manufacturing technology. The electro-pneumatic conversion mechanism 110 is also configured as a part of the electro-pneumatic converter 1 instead of the electro-pneumatic conversion mechanism 10.

[0032] <Third Embodiment> As shown in FIGS. 7 and 8, the electro-pneumatic conversion mechanism 210 according to the third embodiment includes a flow path member 220 and a variable orifice mechanism 230 instead of the flow path member 20 and the variable orifice mechanism 30. The electro-pneumatic conversion mechanism 210 is also configured as a part of the electro-pneumatic converter 1 instead of the electro-pneumatic conversion mechanism 10.

[0033] The flow path member 220 includes a first air flow path R1 and a second air flow path R2, similar to the flow path member 20. The first air flow path R1 is formed linearly, similar to the first embodiment. The second air flow path R2 extends in a direction orthogonal to the direction in which the first air flow path R1 extends, similar to the first embodiment. The cross-section of each of the air flow paths R1 and R2 is circular here. The flow path member 220 is configured as a nozzle having a second end E2 that discharges the air in the first air flow path R1 as a nozzle port. The peripheral edge portion K forming the nozzle port is formed in a convex shape (here, a shape obtained by drilling a cylinder constituting the first air flow path R1 from a truncated cone).

[0034] The flow path member 220 also includes cylindrical orifices 225 and 226 as fixed throttles of the first air flow path R1 (FIG. 8). The orifices 225 and 226 are arranged at intervals along the upstream and downstream directions of the first air flow path R1. The second air flow path R2 is arranged between the orifices 225 and 226, and a change in the air pressure (back pressure) in the space between the orifices 225 and 226 in the first air flow path R1 is taken out as an air pressure signal via the second air flow path R2.

[0035] The variable aperture mechanism 230 includes a diaphragm 31, a piezoelectric element 32 on the diaphragm 31, and a support portion 233 that supports the diaphragm 31. The support portion 233 is fixed to the flow path member 220. The support portion 233 supports the diaphragm 31 in a state where it faces the second end E2 of the first air flow path R1. The support portion 233 is formed in a square ring shape. The diaphragm 31 is disposed in the inner peripheral space of the support portion 233 and is connected to the support portion 233 over its entire circumference. Accordingly, the diaphragm 31 closes the inner peripheral space of the support portion 233. Here, the support portion 233 and the diaphragm 31 are integrally formed. The combination of the support portion 233 and the diaphragm 31 covers the second end E2 and the surrounding space S1. The support portion 233 is formed with a notch S2 that communicates with the space S1. The air discharged from the second end E2 is discharged to the outside of the electropneumatic conversion mechanism 210 through the notch S2. The support portion 233 may be connected to at least both ends sandwiching the piezoelectric element 32 of the diaphragm 31 as long as it supports both ends. For this reason, the support portion 233 may not be annular but may be C-shaped or the like.

[0036] A control circuit 70 is disposed on the support portion 233. The control circuit 70 is connected to the piezoelectric element 32 via a wiring L1. The piezoelectric element 32 deforms by an electrical signal as the control signal from the control circuit 70. As shown by the dotted line in FIG. 7, the diaphragm 31 deforms so as to bulge toward the second end E2 side of the air flow path R1 due to the deformation of the piezoelectric element 32. The diaphragm 31 deforms such that the central portion approaches the second end E2 most closely. Depending on the deformation example, the diaphragm 31 may completely close the second end E2 or may not close it.

[0037] Due to the deformation of the diaphragm 31, the distance between the diaphragm 31 and the second end E2 of the first air flow path R1 changes, and the central portion of the diaphragm 31 approaches the first air flow path R1. As a result, the discharge amount of the air discharged from this second end E2 decreases. Note that the diaphragm 31 may or may not block the second end E2 at the time of maximum deformation. For this reason, the air pressure (also called back pressure) between the orifice 125 in the first air flow path R1 and the diaphragm 31 and the orifice 126 increases. The increase in the air pressure is taken out by the second air flow path R2 as an air pressure signal and output to the pilot relay 80. Thus, the electric signal as the control signal from the control circuit 70 that deforms the diaphragm 31 is converted into an air pressure signal by the electro-pneumatic conversion mechanism 10.

[0038] Also in this embodiment, since the variable throttle mechanism 230 is constituted by the diaphragm 31 and the piezoelectric element 32, miniaturization of the electro-pneumatic conversion mechanism 10 is achieved as compared with the case where a nozzle flapper mechanism constituted by relatively large components such as an exciting coil is employed.

[0039] The pneumatic conversion mechanism 210 may also be formed as at least a part of MEMS. At this time, the control circuit 70 may also be configured as MEMS together with the pneumatic conversion mechanism 210. In this case, the pneumatic conversion mechanism 210 may be regarded as also including the control circuit 70. The pneumatic conversion mechanism 210 can also be formed by an arbitrary MEMS manufacturing process. For example, two members obtained by cutting the flow path member 220 shown in FIG. 1 or the like with a plane passing through the central axes of both the air flow paths R1 and R2 are formed by processing an SOI wafer or the like by etching or the like, and the two formed members are joined to form the flow path member 220. Further, the variable throttle mechanism 230 is integrally formed by processing an SOI wafer or the like by etching or the like. In the variable throttle mechanism 230, the piezoelectric element 32, the control circuit 70, the wiring L1 connecting these, etc. are also formed by a film forming process or the like. Finally, by joining the flow path member 220 and the variable throttle mechanism 230, the pneumatic conversion mechanism 210 equipped with the control circuit 70 is formed. As shown in the cross-sectional view of FIG. 8, the pneumatic conversion mechanism 210 is formed in a stacked structure and formed as one chip. Thereby, the pneumatic conversion mechanism 10 is miniaturized.

[0040] <Fourth Embodiment> As shown in FIG. 9, the pneumatic conversion structure 300 according to the fourth embodiment includes a plurality of pneumatic conversion mechanisms 10. The number of the pneumatic conversion mechanisms 10 may be plural and is not limited to three in FIG. 9. The pneumatic conversion structure 300 is also used in the pneumatic converter 1. The plurality of first air flow paths R1 respectively included in the plurality of pneumatic conversion mechanisms 10 are connected in parallel to an air supply source AS which is an air supply source via a branch flow path R3 (schematically drawn) that branches a flow path connected to the air supply source AS. Therefore, the air from the air supply source AS is divided by the branch flow path R3 and supplied to each first air flow path R1. The same amount of air may be supplied to each first air flow path R1. The plurality of second air flow paths R2 respectively included in the plurality of pneumatic conversion mechanisms 10 are connected in parallel to a pilot relay 80 which is an output destination of an air pressure signal via a confluence flow path R4 (schematically drawn) that combines the air from each second air flow path R2. Therefore, the air pressure signals extracted by each second air flow path R2 are added together in the confluence flow path R4 and supplied to the pilot relay 80.

[0041] The plurality of flow path members 20 and the plurality of diaphragms 31 that respectively constitute the plurality of electropneumatic conversion mechanisms 10 may be integrally formed, for example, by MEMS manufacturing technology. Also, the plurality of piezoelectric elements 32 that respectively constitute the plurality of electropneumatic conversion mechanisms 10 may be formed collectively by MEMS manufacturing technology. The control circuit 70 may also be formed on the flow path member 20 by the wiring L2 (shown schematically) and MEMS manufacturing technology. One control circuit 70 may supply control signals (electrical signals) to each of the plurality of piezoelectric elements 32. Note that a plurality of control circuits 70 may be formed one-to-one for the plurality of piezoelectric elements 32.

[0042] As shown in FIG. 10, at least a part of the plurality of electropneumatic conversion mechanisms 10 of the electropneumatic conversion structure 300 may be changed to one or more electropneumatic conversion mechanisms 110 or 210. In the example shown in FIG. 10, the electropneumatic conversion structure 300 includes a plurality of electropneumatic conversion mechanisms 110 or a plurality of electropneumatic conversion mechanisms 210.

[0043] According to the present embodiment, since a plurality of electropneumatic conversion mechanisms 10 and the like are provided, it is possible to secure a larger flow rate of the air that constitutes the pneumatic signal than in the case of adopting one electropneumatic conversion mechanism 10 or the like. This is particularly useful when it is not possible to secure a large flow rate of air in the first air flow path R1 by microfabrication by making the electropneumatic conversion mechanism 10 or the like into MEMS. If a large flow rate can be secured, the subsequent pilot relay can be driven at high speed (the transient response characteristics as an electropneumatic converter are improved).

[0044] <Modification Example> The above electro-pneumatic conversion mechanisms 10, 110, and 210, the electro-pneumatic conversion structure 300, etc. may be adopted for an electro-pneumatic positioner instead of the electro-pneumatic converter 1. The shapes of elements such as the members constituting the electro-pneumatic conversion mechanisms 10, 110, and 210 are arbitrary. For example, the first air flow path R1 and the second air flow path R2 of the electro-pneumatic conversion mechanisms 10 and 110 may have a circular cross-section. The diaphragm 31 may be formed separately from the second member 22 and the support portion 233 and may be connected to them by being attached thereto. The support portion 233 may be formed in an annular shape or the like. In the electro-pneumatic conversion mechanism 10, the orifice 26 may be omitted when the deformation amount of the diaphragm 31 can be sufficiently ensured.

[0045] <Scope of the present invention> As described above, the present invention has been described with reference to the embodiments and modification examples. However, the present invention is not limited to the above embodiments and modification examples. For example, the present invention includes various changes to the above embodiments and modification examples that can be understood by those skilled in the art within the scope of the technical idea of the present invention. Each configuration described in the above embodiments and modification examples can be appropriately combined within a non-contradictory range.

Explanation of reference numerals

[0046] 1... electro-pneumatic converter, 10... electro-pneumatic conversion mechanism, 20... flow path member, 21... first member, 21A... groove, 22... second member, 22A... hole, 25, 26... orifice, 30... variable throttle mechanism, 31... diaphragm, 32... piezoelectric element, 70... control circuit, 80... pilot relay, 110... electro-pneumatic conversion mechanism, 120... flow path member, 125, 126... orifice, 125A, 125B... convex portion, 210... electro-pneumatic conversion mechanism, 220... flow path member, 225, 226... orifice, 230... variable throttle mechanism, 233... support portion, 300... electro-pneumatic conversion structure, AS... air supply source, E1... first end, E2... second end, K... peripheral portion, L1, L2... wiring, R1... first air flow path, R2... second air flow path, R3... branch flow path, R4... confluence flow path, S... sensor, S1... space, S2... notch, U... upper device, V... regulating valve.

Claims

1. An electropneumatic conversion mechanism for converting an electrical signal into a pneumatic signal, comprising a first air flow path having a first end to which air is supplied and a second end from which the air is discharged, and a second air flow path connected at an intermediate position in the first air flow path for extracting a change in air pressure in the first air flow path as a pneumatic signal, the flow path member; a fixed orifice provided between the first end and the intermediate position of the first air flow path; an orifice comprising a convex portion protruding from the bottom of the first air flow path provided between the intermediate position and the second end of the first air flow path; a variable orifice mechanism for changing the air pressure by changing the discharge amount of the air discharged from the second end of the first air flow path, wherein the variable orifice mechanism is provided at a position facing the orifice with the first air flow path interposed therebetween, and includes a diaphragm that deforms so that a central portion approaches the orifice to change the discharge amount; a piezoelectric element formed on the diaphragm and deformed by an electrical signal to deform the diaphragm, the electropneumatic conversion mechanism.

2. The electropneumatic conversion mechanism according to claim 1, wherein the flow path member and the variable orifice mechanism are at least part of MEMS (MicroElectroMechanical Systems). The electropneumatic conversion mechanism according to claim 1.

3. having a plurality of electropneumatic conversion mechanisms, each of which is the electropneumatic conversion mechanism according to claim 1 or 2, wherein the first air flow paths of the plurality of electropneumatic conversion mechanisms are connected in parallel to the air supply source, and the second air flow paths of the plurality of electropneumatic conversion mechanisms are connected in parallel to the output destination of the pneumatic signal, the electropneumatic conversion structure.

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