FLUID CONTROL DEVICE
The fluid control device addresses detachment issues by using a recessed second flat plate to concentrate stress away from the joint, ensuring structural stability and improved performance.
Patent Information
- Application Number
- DE112023004446
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-11-22
- Publication Date
- 2025-08-14
AI Technical Summary
The existing fluid control device experiences detachment between the upper plate and the side wall due to stress generated at the joint portion caused by vibrations, which affects the structural integrity and performance.
A fluid control device design featuring a second flat plate with an annular recess and a side wall connected to both the first and second flat plates, concentrating stress on non-joined portions to reduce detachment, with the recess positioned to minimize stress concentration at the joint.
The design effectively reduces detachment between the second flat plate and the side wall, maintaining structural integrity and enhancing pumping performance by minimizing stress at the connection point.
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Abstract
Description
Technical area
[0001] The present invention relates to a fluid control device using vibrations of a piezoelectric body. Technical background
[0002] Patent Document 1 describes a fluid control device including a piezoelectric body. The fluid control device according to Patent Document 1 includes a vibration plate to which the piezoelectric body is connected, a top plate, and a side wall.
[0003] The vibrating plate and the upper plate are arranged at a distance from each other. The side wall is connected to an outer peripheral portion of the upper plate to enclose a space between the vibrating plate and the upper plate. In this structure, the vibrating plate, the upper plate, and the side wall form a pumping chamber. The vibrating plate and the upper plate each have an opening. Thus, the pumping chamber is connected to a space outside the fluid control device through the opening in the vibrating plate and the opening in the upper plate.
[0004] The fluid control device according to Patent Document 1 applies a drive signal to the piezoelectric body to vibrate the vibrating plate. The fluid control device then draws a fluid (e.g., a gas) into the pumping chamber through the opening in the vibrating plate, transports the fluid into the pumping chamber, and expels the fluid through the opening in the upper plate. List of referencesPatent document
[0005] Patent Document 1: International Publication No. 2020 / 111063 PRESENTATION of the inventionTechnical problem
[0006] However, in the fluid control device according to Patent Document 1, the top plate also vibrates because the pressure distribution in the pumping chamber changes over time due to vibrations of the vibration plate. In a structure where the top plate and the side wall are made of separate components and are connected to each other, stress generated by the vibrations of the top plate is generated at the joint portion between the top plate and the side wall. This stress can cause peeling between the top plate and the side wall at the joint surface.
[0007] Therefore, the present invention aims to provide a structure in which a top plate and a side wall are connected and which reduces loosening between the top plate and the side wall at a connecting surface. Solution to the problem
[0008] An embodiment of the present invention provides a fluid control device comprising a first flat plate, a second flat plate, and a sidewall. The first flat plate includes a vibrator on which a piezoelectric device is disposed, a frame surrounding the vibrator, a support member connecting the vibrator and the frame, and a first opening formed between the vibrator and the frame. The second flat plate has a first major surface facing the vibrator and a second opening. The sidewall is disposed between the frame of the first flat plate and the second flat plate so as to be connected to the first flat plate and the second flat plate.
[0009] The second flat plate has an annular first recess formed from the first flat surface. When the fluid control device is viewed from a plan view in an arrangement direction in which the second flat plate, the side wall, and the first flat plate are sequentially arranged, an outer peripheral edge of the first recess is positioned outside an inner wall surface of the side wall.
[0010] In this structure, a portion of the second flat plate where the stress caused by the vibration of the second flat plate is concentrated is a portion where a thin portion defined by the first recess in the second flat plate and a thick portion without the first recess are connected. The portion where the second flat plate and the side wall are connected is different from the portion where the thin portion and the thick portion are connected. This structure reduces the stress generated at the portion where the second flat plate and the side wall are connected. Advantageous effects of the invention
[0011] According to the invention, the loosening between the second flat plate (upper plate) and the side wall at a connecting surface can be reduced. Brief description of the drawings Fig. 1 is an exploded perspective view of a fluid control device according to a first embodiment. Fig. 2(A) is a cross-sectional view of a structure of the fluid control device according to the first embodiment, and Fig. 2(B) is an enlarged cross-sectional view of a connecting portion between a second flat plate and a side wall. Fig. 3(A) is a diagram illustrating a simulation result of the stress generated at a connecting portion between a second flat plate and a side wall in the fluid control device according to the first embodiment of the present invention, and Fig. 3(B) is a diagram illustrating a simulation result of the stress generated at a connecting portion between a second flat plate and a side wall in a fluid control device according to a comparative example. Fig. 4(A) is a diagram showing the relationship between the voltage and the ratio of a no-connection width to a facing width of the second flat plate and the side wall, and Fig. Figure 4(B) is a graph showing the relationship between the stress and the ratio of the depth of a recess to the thickness of the second flat plate. Fig. 5 is a cross-sectional view of a structure of a fluid control device according to a second embodiment. Fig. 6 is a cross-sectional view of a structure of a fluid control device according to a third embodiment. Fig. 7 is a cross-sectional view of a structure of a fluid control device according to a fourth embodiment. Fig. 8 is an enlarged cross-sectional view of a connecting portion between a second flat plate and a side wall of a fluid control device according to a fifth embodiment. Description of the embodimentsFirst embodiment
[0012] A fluid control device according to a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an exploded perspective view of the fluid control device according to the first embodiment. Fig. 2(A) is a cross-sectional view of the structure of the fluid control device according to the first embodiment. Fig. Figure 2(B) is an enlarged cross-sectional view of a connecting portion between a second flat plate and a side wall. For ease of description, in the drawings of the embodiments described below, some components are partially or completely exaggerated. For clarity, some reference numerals for components that are believed to be clearly understood are omitted. Structure of the fluid control device 10
[0013] As in Fig. 1, Fig. 2(A) and Fig. 2(B), a fluid control device 10 includes a first flat plate 20, a piezoelectric device 30, a second flat plate 40, and a side wall 50.
[0014] The first flat plate 20 is a circular flat plate in plan view. The first flat plate 20 has a circular main surface 211 and a circular main surface 212. The main surface 211 and the main surface 212 are opposite each other.
[0015] The first flat plate 20 includes a vibrator 21, a frame 22, support elements 23, and first openings 230. In plan view, the vibrator 21 has a circular shape. In plan view, the frame 22 has a ring shape. The frame 22 surrounds the vibrator 21 along the outer circumference of the vibrator 21.
[0016] The support members 23 and the first openings 230 are arranged along the outer peripheral edge of the vibrator 21 and between the vibrator 21 and the frame 22. The first openings 230 extend through the main surface 211 and the main surface 212 of the first flat plate 20.
[0017] The support elements 23 connect the outer peripheral edge of the vibrator 21 and the inner peripheral edge of the frame 22. The fluid control device 10 has, for example, a plurality of support elements 23. In the example in Fig. 1, the support members 23 are arranged along the outer periphery of the vibrator 21 at angular intervals of 120°. In the fluid control device 10, the support members 23 are shaped to divide a single opening into the first openings 230 at portions of the outer periphery of the first openings 230. The support members 23, having a suitable width and shape, allow the vibrator 21 to vibrate with respect to the frame 22. In other words, the support members 23 support the vibrator 21 while allowing the vibrator 21 to vibrate with respect to the frame 22.
[0018] Although the vibrator 21 preferably has a circular shape, the vibrator 21 may also have a substantially circular shape, such as an ellipse, or a polygonal shape. The profile of the frame 22, that is, the profile of the first flat plate 20, is not limited to a circle and can be appropriately determined in accordance with the profile design of the fluid control device 10.
[0019] The first flat plate 20 is formed, for example, from metal. The first flat plate 20 can be any plate that allows the vibrator 21 to induce bending vibrations due to distortion of the piezoelectric device 30 (see below). The bending vibrations are vibrations that cause the main surface 211 and the main surface 212 to undulate when the vibrator 21 is viewed from the side.
[0020] The piezoelectric device 30 includes a disk-shaped piezoelectric body and drive electrodes. The drive electrodes are arranged on both main surfaces of the disk-shaped piezoelectric body.
[0021] The piezoelectric device 30 is arranged on the main surface 212 of the vibrator 21. The piezoelectric device 30 warps when a drive signal is applied to the drive electrode. This warping causes the vibrator 21 to vibrate in the manner described above.
[0022] The second flat plate 40 has a round flat plate shape in plan view. The second flat plate 40 is made of a material that causes less vibration and has a thickness that causes less vibration than the first flat plate 20. The profile of the second flat plate 40 is substantially the same as the profile of the first flat plate 20. The second flat plate 40 has a circular first main surface 401 and a circular second main surface 402. The first main surface 401 and the second main surface 402 are opposite each other.
[0023] The second flat plate 40 has a second opening 400. The second opening 400 is a cylindrical through-hole extending through the first main surface 401 and the second main surface 402 of the second flat plate 40. The second opening 400 is formed to include the center of the second flat plate 40 when the second flat plate 40 is viewed from above.
[0024] The second flat plate 40 has a recess 41. The recess 41 is located adjacent to the outer peripheral edge of the second flat plate 40. The recess 41 is recessed from the first main surface 401. In plan view, the recess 41 has a ring shape. The recess 41 corresponds to a "first recess" within the meaning of the present invention.
[0025] The recess 41 has an inner peripheral surface 401i, an outer peripheral surface 401o, and a bottom surface (an upper surface) 401f. The inner peripheral surface 401i and the outer peripheral surface 401o are parallel to the depth direction of the recess 41. The inner peripheral surface 401i is a surface positioned closer to the center of the annular shape, and the outer peripheral surface 401o is a surface positioned at a greater distance from the center in a radial direction of the annular shape than the inner peripheral surface 401i. The bottom surface (the upper surface) 401f is a surface orthogonal to the depth direction of the recess, and this represents a depth H41 of the recess.
[0026] The second flat plate 40 is arranged such that its main surfaces are parallel to the first flat plate 20. The first main surface 401 of the second flat plate 40 and the main surface 211 of the first flat plate 20 face each other. The center of the second flat plate 40 in plan view and the center of the vibrator 21 of the first flat plate 20 are substantially congruent in plan view.
[0027] As with the first flat plate 20, the profile of the second flat plate 40 is not limited to a circular shape and can be appropriately determined according to the design of the profile of the fluid control device 10.
[0028] The side wall 50 is an annular cylinder. The side wall 50 is formed of a material that causes almost no bending vibrations and has a thickness that causes almost no bending vibrations. The side wall 50 is separate from the first flat plate 20, but the side wall 50 and the first flat plate 20 may be formed as one piece.
[0029] The side wall 50 has an inner wall surface 501 and an outer wall surface. In the plan view of the fluid control device 10, the inner wall surface 501 is circular. The inner wall surface 501 is an inner wall surface of the annular cylinder, and the outer wall surface is an outer wall surface of the annular cylinder. Type of connection between the first flat plate 20, the second flat plate 40 and the side wall 50
[0030] The side wall 50 is arranged between the first flat plate 20 and the second flat plate 40. The end surface of the side wall 50 that is closer to the first flat plate 20 in the height direction abuts and is connected to the main surface 211 of the frame 22 of the first flat plate 20. The end surface of the side wall 50 that is positioned closer to the first flat plate 20 and the main surface 211 of the frame 22 are connected, for example, with an adhesive.
[0031] An end surface 509 of the side wall 50, which is closer to the second flat plate 40 in the height direction, is bonded to the first main surface 401 of the second flat plate 40. The end surface 509 and the first main surface 401 are bonded with an adhesive 510. The end surface 509 and the first main surface 401 are bonded with the adhesive 510, but can be bonded by any method as long as the end surface 509 and the first main surface 401, which are originally separated from each other, are physically bonded to each other.
[0032] The fluid control device 10 with this structure has a space surrounded by the first flat plate 20, the second flat plate 40, and the side wall 50. This space serves as the pumping chamber 100 of the fluid control device 10. More concrete structure of the second flat plate 40 and the side wall 50
[0033] In the plan view of the fluid control device 10 (in an arrangement direction in which the second flat plate 40, the side wall 50, and the first flat plate 20 are arranged sequentially), a portion of the end surface 509 of the side wall 50 positioned closer to the outer wall surface of the wall overlaps the first main surface 401 of the second flat plate 40. A portion of the end surface 509 positioned closer to the outer wall surface and the first main surface 401 are bonded with the adhesive 510.
[0034] In the plan view of the fluid control device 10, a portion of the end surface 509 of the side wall 50, which is closer to the inner wall surface 501, overlaps the recess 41 in the second flat plate 40. Thus, a portion of the edge (a corner in the side view) at which the inner wall surface 501 and the end surface 509 of the side wall 50 intersect is not connected to the first main surface 401, that is, the second flat plate 40. Tension in the connecting section between the second flat plate 40 and the side wall 50
[0035] Fig. 3(A) is a diagram showing a simulation result of the stress generated at a connecting portion between a second flat plate and a side wall in the fluid control device according to the first embodiment of the present invention. Fig. 3(B) is a diagram illustrating a simulation result of stresses generated at a joint portion between a second flat plate and a side wall in a fluid control device according to a comparative example. Fig. 3(A) and Fig. 3(B) illustrates the voltage ST generated when the second flat plate vibrates in a direction to separate the second flat plate from the side wall.
[0036] In the fluid control device 10 having the above structure, a portion of the second flat plate 40 having the recess 41 is a thin portion. Thus, the second flat plate 40 includes a thick portion positioned closer to the center than the recess 41 in the second flat plate 40, a thin portion defined by the recess 41, and a thick portion positioned outside the recess 41. In this structure, stress is concentrated at the joint portion between the thick portion and the thin portion.
[0037] As in Fig. 3(A), this means that a portion of the fluid control device 10 where the bottom surface (top surface) 401f and the outer peripheral surface 401o of the recess 41 intersect is subjected to the greatest stress (the corner in the side view). The stress generated at an inner end portion ED45 where the second flat plate 40 and the side wall 50 are joined is lower than that at the edge portion (the corner in the side view) where the bottom surface (top surface) 401f and the outer peripheral surface 401o intersect.
[0038] Thus, in the control device 10, the most stressed portion is not the inner end portion ED45 where the second flat plate 40 and the side wall 50 are connected to each other, but the portion of the edge defining the recess 41 in the second flat plate 40, which is a portion defined without any physical connection.
[0039] As in Fig. 3(B), in a fluid control device according to a comparative example, the most stressed portion is an edge portion where the inner wall surface 501 and the end surface 509 of the side wall 50 intersect. The edge portion corresponds to the inner end portion ED45P according to the comparative example, where the second flat plate 40 and the side wall 50 are connected. More specifically, in the fluid control device according to the comparative example, the portion subjected to the most stress is a portion formed by the physical connection of the second flat plate 40 and the side wall 50.
[0040] As described above, in the fluid control device according to the comparative example, the portion subjected to the greatest stress overlaps the connecting portion, whereas in the fluid control device 10, the portion subjected to the greatest stress does not overlap the connecting portion, and the stress generated at the connecting portion is lower. Thus, the fluid control device 10 can reduce the stress generated at the connecting portion between the second flat plate 40 and the side wall 50. Thus, the fluid control device 10 can reduce the loosening between the second flat plate 40 and the side wall 50 at the connecting portion.
[0041] As described above, the fluid control device 10 includes the second flat plate 40 with the recess 41. Furthermore, the recess 41 in the fluid control device 10 prevents the second flat plate 40 from contacting the edge portion where the inner wall surface 501 and the end surface 509 of the side wall 50 intersect, and allows the second flat plate 40 to be joined to the end surface 509 of the side wall 50 at a portion outside the edge portion. Thus, the fluid control device 10 can reduce the loosening at the joining portion between the second flat plate 40 and the side wall 50.
[0042] In the fluid control device 10, the recess 41 preferably does not overlap the vibrator 21 in plan view. More specifically, when the fluid control device 10 is viewed in plan view, the inner wall surface 401i of the recess 41 is preferably located outside the outer peripheral edge of the vibrator 21. With this structure, the recess 41 does not increase the distance between the vibrator 21 and the second flat plate 40 in the pumping chamber 100. This structure can thus reduce deterioration in the pumping performance of the fluid control device 10. Connection width and depth of the recess
[0043] Fig. Figure 4(A) is a graph showing the relationship between the voltage and the ratio between the no-connection width and the facing width with which the second flat plate and the side wall face each other. The solid line in Fig. 4(A), which indicates the voltage, shows the voltage in the comparison example.
[0044] As in Fig. 2(B), a “Facing Width” W50, with which the second flat plate 40 and the side wall 50 face each other, is a distance between the inner wall surface 501 and the outer wall surface of the side wall 50. In Fig. 2(B), the profile of the second flat plate 40 and the profile of the side wall 50 match, so this distance can be defined as the facing width W50. However, if the profile of the second flat plate 40 is smaller than the profile of the side wall 50, the facing width W50 is the distance between the inner wall surface 501 of the side wall 50 and the outer peripheral edge of the second flat plate 40 in plan view.
[0045] A no-connection width W41 is a distance between the inner wall surface 501 and the outer circumferential surface 401o of the recess 41 in plan view. The ratio in Fig. 4(A) is calculated by dividing the no-connection width W41 by the facing width W50 and expressed as a percentage.
[0046] As in Fig. As shown in Figure 4(A), the stress generated at the connecting portion of the fluid control device 10 is lower than the stress generated at the connecting portion of the fluid control device according to the comparative example when the no-connection width W41 is less than or equal to approximately 75% of the facing width W50. Therefore, in the fluid control device 10, the no-connection width W41 is preferably less than or equal to approximately 75% of the facing width W50.
[0047] Fig. Figure 4(B) is a graph showing the relationship between the stress and the ratio between the depth of a recess and the thickness of the second flat plate. The solid line shown in Fig. 4(B) indicates the voltage, shows the voltage in the comparison example. The ratio in Fig. 4(B) is calculated by dividing the depth H41 of the recess 41 by the thickness H40 of the second flat plate 40 and expressing it as a percentage. The depth H41 of the recess 41 is obtained by subtracting the thickness at the thinnest portion of the recess 41 from the thickness H40 of the second flat plate 40.
[0048] As in Fig. As shown in Figure 4(B), when the depth H41 of the recess 41 is less than or equal to about 65% of the thickness H40 of the second flat plate 40, the stress generated at the connecting portion in the fluid control device 10 is lower than the stress generated at the connecting portion in the fluid control device according to the comparative example. Thus, in the fluid control device 10, the depth H41 of the recess 41 is preferably less than or equal to about 65% of the thickness H40 of the second flat plate 40. Second embodiment
[0049] A fluid control device according to a second embodiment of the present invention will be described with reference to the drawings. Fig. 5 is a cross-sectional view of a structure of a fluid control device according to a second embodiment. As shown in Fig. 5, a fluid control device 10A according to the second embodiment differs from the fluid control device 10 according to the first embodiment in that it includes a second flat plate 40A. Other components of the fluid control device 10A are the same as those of the fluid control device 10 according to the first embodiment and will therefore not be described.
[0050] The second flat plate 40A has a recess 420. The recess 420 is recessed from the first main surface 401 and is circular in plan view. The recess 420 is connected to the second opening 400. The recess 420 corresponds to a "second recess" within the meaning of the present invention.
[0051] The fluid control device 10A having this structure can reduce the resistance of the fluid flow path in the space defined by the bottom surface of the recess 420 and a portion of the vibrator 21 overlapping the recess 420 in plan view. Third embodiment
[0052] A fluid control device according to a third embodiment of the present invention will be described with reference to the drawings. Fig. 6 is a cross-sectional view of a structure of a fluid control device according to a third embodiment. As shown in Fig. As shown in Figure 6, a fluid control device 10B according to the third embodiment differs from the fluid control device 10 according to the first embodiment in that it includes a valve element. Other components of the fluid control device 10B are the same as those of the fluid control device 10 according to the first embodiment and will therefore not be described.
[0053] The fluid control device 10B includes a valve element. The valve element includes a film 60 and a fastening element 70.
[0054] The film 60 is a circular film. The fixing member 70 is a cylinder with a smaller diameter than the film 60. The film 60 is fixed to the main surface 211 of the vibrator 21 by the fixing member 70. A portion of the film 60 near the outer peripheral edge is not fixed to the fixing member 70 and is deformed by a fluid flowing in the pumping chamber 100. The fluid control device 10B draws in the fluid through the second opening 400 using the deformation of the film 60 and expels the fluid through the first openings 230.
[0055] The fluid control device 10B with this structure can achieve more stable flow control while reducing the loosening between the second flat plate 40 and the side wall 50.
[0056] At this time, the recess 41 preferably does not overlap any valve element when the fluid control device 10B is viewed from above. For example, the inner peripheral surface 401i of the recess 41 is preferably located outside the outer peripheral edge of the film 60 when the fluid control device 10B is viewed from above.
[0057] The fluid control device 10B can thus reduce the interference of the flow control function by the recess 41.
[0058] The structure according to the third embodiment having the valve element is also applicable to a structure according to another embodiment in addition to the structure according to the first embodiment. Fourth embodiment
[0059] A fluid control device according to a fourth embodiment of the present invention will be described with reference to the drawings. Fig. 7 is a cross-sectional view of a structure of a fluid control device according to a fourth embodiment. As shown in Fig. 7, a fluid control device 10C according to the fourth embodiment differs from the fluid control device 10 according to the first embodiment with respect to the shape of a recess 41C. Other components of the fluid control device 10C are the same as those of the fluid control device 10 according to the first embodiment and will therefore not be described.
[0060] In the fluid control device 10C, the second flat plate 40 has the recess 41C. The recess 41C is circular in plan view. The outer peripheral surface 401o of the recess 41C is located outside the inner wall surface 501 of the side wall 50 in the plan view of the fluid control device 10C. The recess 41C corresponds to a "first recess" according to the invention and can also function as a "second recess" according to the invention.
[0061] The fluid control device 10C having this structure can reduce the loosening between the second flat plate 40 and the side wall 50 at the mating surface. Fifth embodiment
[0062] A fluid control device according to a fifth embodiment of the present invention will be described with reference to the drawings. Fig. 8 is an enlarged cross-sectional view of a connecting portion between a second flat plate and a side wall of a fluid control device according to a fifth embodiment. As shown in Fig. As shown in Fig. 8, a fluid control device 10D according to the fifth embodiment differs from the fluid control device 10 according to the first embodiment with respect to the shape of a recess 41D. Other components of the fluid control device 10D are the same as those of the fluid control device 10 according to the first embodiment and will therefore not be described.
[0063] The recess 41D in the second flat plate 40 has an arcuate cross-section when viewed from the side. More specifically, the recess 41D has a wall surface 42 with an arcuate cross-section. In the plan view of the fluid control device 10D, the outermost end of the wall surface 42 of the recess 41D is located outside the inner wall surface 501 of the side wall 50.
[0064] The fluid control device 10D having this structure can reduce the loosening between the second flat plate 40 and the side wall 50 at the joint surface.
[0065] The recess may have any shape other than those described above in the embodiments. The shape of the recess may be appropriately selected as long as the outermost end of the recess lies outside the edge where the inner wall surface 501 and the end portion 509 of the side wall 50 intersect in the plan view of the fluid control device. (1) A fluid control device comprising: a first flat plate with a vibrator on which a piezoelectric device is arranged, a frame that surrounds the vibrator, a support element that connects the vibrator and the frame, and a first opening located between the vibrator and the frame; a second flat plate having a first major surface facing the vibrator and a second opening; and a side wall arranged between the frame of the first flat plate and the second flat plate so as to be connected to the first flat plate and the second flat plate, wherein the second flat plate has an annular first recess formed from the first main surface, and wherein, when the fluid control device is viewed in a plan view in an arrangement direction in which the second flat plate, the side wall and the first flat plate are sequentially arranged, an outer peripheral edge of the first recess is positioned outside an inner wall surface of the side wall. (2) Fluid control device according to point (1), wherein in the plan view of the fluid control device in the arrangement direction, an inner peripheral edge of the recess is positioned outside the vibrator. (3) The fluid control device according to item (1) or (2), wherein the second flat plate has a second recess connected to the second opening and recessed from the first main surface. (4) Fluid control device according to any one of items (1) to (3), comprising: a valve element disposed on a surface of the vibrator closer to the second flat plate. (5) Fluid control device according to point (4), wherein, when the fluid control device is viewed in the arrangement direction in plan view, an inner peripheral edge of the first recess is positioned outside the valve element. (6) Fluid control device according to any one of items (1) to (5), wherein a no-connection width between the second flat plate and the side wall is less than or equal to 75% of a distance between the inner wall surface and an outer peripheral edge of the side wall at a portion connected to the second flat plate. (7) Fluid control device according to any one of items (1) to (5), wherein a depth of the first recess is less than or equal to 65% of a thickness of the second flat plate. LIST OF REFERENCE SYMBOLS 10, 10A, 10B, 10C, 10D Fluid control device 20 first flat plate 21 Vibrator 22 frames 23 Support element 30 piezoelectric device 40, 40A second flat plate 41, 41C, 41D recess 42 wall area 50 side wall 60 foil 70 Fastening element 100 pump chamber 211, 212 Main interface 230 first opening 400 second opening 401 first main interface 401i inner circumferential surface 401o outer peripheral surface 402 second main interface 420 recess 501 inner wall area 509 End face 510 Adhesive
Claims
[1] Fluid control device comprising: a first flat plate with a vibrator on which a piezoelectric device is arranged, a frame arranged to surround the vibrator, a support element that connects the vibrator and the frame, and a first opening formed between the vibrator and the frame; a second flat plate having a first major surface facing the vibrator and a second opening; and a side wall arranged between the frame of the first flat plate and the second flat plate so as to be connected to the first flat plate and the second flat plate, wherein the second flat plate has a first annular recess formed from the first main surface, and wherein, when the fluid control device is viewed in plan view in an arrangement direction in which the second flat plate, the side wall and the first flat plate are sequentially arranged, an outer peripheral edge of the first recess is positioned outside an inner wall surface of the side wall. [2] The fluid control device according to claim 1, wherein, when the fluid control device is viewed in the arrangement direction in a plan view, an inner peripheral edge of the first recess is arranged outside the vibrator. [3] A fluid control device according to claim 1 or 2, wherein the second flat plate has a second recess connected to the second opening and recessed from the first main surface. [4] Fluid control device according to one of claims 1 to 3, comprising: a valve element disposed on a surface of the vibrator closer to the second flat plate. [5] The fluid control device according to claim 4, wherein, when the fluid control device is viewed in the arrangement direction in a plan view, an inner peripheral edge of the first recess is located outside the valve element. [6] The fluid control device according to any one of claims 1 to 5, wherein a no-connection width between the second flat plate and the side wall is less than or equal to 75% of a distance between the inner wall surface and an outer peripheral edge of the side wall at a portion connected to the second flat plate. [7] The fluid control device according to any one of claims 1 to 5, wherein a depth of the first recess is less than or equal to 65% of a thickness of the second flat plate.