Actuator and fluid control device

Abstract

To achieve an actuator which can easily secure rigidity necessary for a connection part, and which can be easily miniaturized.SOLUTION: An actuator includes: a frame body 22 having a polygonal opening; a circular first flat plate 21 which is arranged inside the opening, and in which a drive body is mounted; and a plurality of connection members 23 arranged between the first flat plate inside the opening and the frame body, and for connecting an outer peripheral end of the first flat plate and the frame body so as to leave part of the opening. The connection member includes a first portion 231 and a second portion 232. The first portion has a shape extending in the direction being separated from the first flat plate with the outer peripheral end of the first flat plate being one end, one end in the extending direction is connected to the outer peripheral end, and the other end in the extending direction is connected to the second portion. The second portion has a shape extending in the direction different from the first portion, both ends in the extending direction of the second portion are connected to an inner peripheral end 224 in the frame body, and a plurality of positions where the connection members are connected to the frame body is arranged at equal intervals along an outer periphery of the first flat plate.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an actuator having a structure for vibrating a flat plate by a driving body such as a piezoelectric element. [Background technology]

[0002] Patent Document 1 discloses a pump. The pump in Patent Document 1 includes a vibration plate, a frame, and a connecting portion. The frame is disposed surrounding the vibration plate, and is connected to the outer edge of the vibration plate by the connecting portion. The portion between the vibration plate and the frame other than the connecting portion is an air gap, and the connecting portion is beam-shaped. As a result, the connecting portion supports the vibration plate relative to the frame so that it can vibrate. That is, an actuator is realized by the vibration plate, the frame, and the connecting portion.

[0003] The coupling portion has a first portion, a second portion, and a third portion.

[0004] The first portion has a shape that extends in a radial direction (a direction from the center of the diaphragm toward the outside of the diaphragm). One end of the first portion in the extending direction is connected to the outer periphery of the diaphragm. The other end of the first portion in the extending direction is connected to the second portion.

[0005] The second portion is shaped to extend along the outer periphery of the diaphragm. A substantial center of the second portion in the extending direction is connected to the first portion, and both ends of the second portion in the extending direction are connected to the frame via the third portion extending in the radial direction. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2012 / 140967 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the conventional configuration shown in Patent Document 1, the gap is narrow, making it difficult to manufacture. In this case, if one tries to reliably provide the gap without increasing the size of the pump, the width of the second portion will be narrow. This makes it difficult to ensure the rigidity required for the connecting portion, and there is a possibility that reliability will decrease.

[0008] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide an actuator that can easily ensure the required rigidity in the connecting portion and can be easily miniaturized. [Means for solving the problem]

[0009] An actuator according to one embodiment of the present invention includes a frame having a polygonal opening, a circular first flat plate disposed inside the opening and having a driver attached thereto, and a plurality of connecting members disposed between the first flat plate and the frame inside the opening and connecting an outer circumferential edge of the first flat plate to the frame so as to leave a part of the opening. The connecting members include a first portion and a second portion, the first portion has a shape extending in a direction away from the first flat plate with the outer circumferential edge of the first flat plate as one end, one end in the extending direction being connected to the outer circumferential edge and the other end in the extending direction being connected to the second portion, the second portion has a shape extending in a direction different from the first portion, both ends in the extending direction of the second portion being connected to an inner circumferential edge of the frame, and the plurality of positions where the connecting members connect to the frame are disposed at equal intervals along the outer circumferential edge of the first flat plate. Effect of the Invention

[0010] According to this invention, it is possible to realize an actuator which can easily ensure the required rigidity in the connecting portion and can be easily miniaturized. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is an exploded perspective view of a fluid control device 10 including an actuator 11 according to a first embodiment. [Diagram 2] FIG. 2A is a plan view of the actuator 11 according to the first embodiment, and FIG. 2B is a cross-sectional view taken along line AA of FIG. [Diagram 3]FIG. 3 is a plan view of an actuator having a conventional configuration. [Figure 4] FIG. 4 is a plan view of the actuator according to the second embodiment. [Diagram 5] FIG. 5 is a plan view of the actuator according to the third embodiment. [Figure 6] FIG. 6 is a plan view of the actuator according to the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (First embodiment) An actuator and 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 a fluid control device 10 including an actuator 11 according to the first embodiment. FIG. 2(A) is a plan view of the actuator 11 according to the first embodiment, and FIG. 2(B) is a cross-sectional view taken along line AA of FIG. 3 is a plan view of an actuator having a conventional configuration. In FIGS. 2(A) and 3, the driver is omitted. In each drawing, the shapes of the respective components are partially or entirely exaggerated in order to make the configurations of the actuator 11 and the fluid control device 10 easier to understand.

[0013] (Configuration of actuator 11) 1, 2(A) and 2(B), the actuator 11 includes a flat plate member 20 and a driver 30. The driver 30 is, for example, a piezoelectric element, and is attached to the flat plate member 20. More specifically, the driver 30 is attached to a main surface 201 of a central plate 21 of the flat plate member 20, the detailed configuration of which will be described later.

[0014] (Configuration of the flat plate member 20) The flat plate member 20 is made of a metal plate or the like, and has a main surface 201 and a main surface 202. The flat plate member 20 includes a central flat plate 21, a frame body 22, and a plurality of connecting members 23. The central flat plate 21, the frame body 22, and the plurality of connecting members 23 are integrally formed using, for example, a single flat plate.

[0015] The central flat plate 21 is a flat plate, and the shape of the central flat plate 21 when viewed from above (the shape when viewed in the thickness direction (z-axis direction)) is circular. As described above, the driver 30 is attached to the main surface 201 of the central flat plate 21. The central flat plate 21 corresponds to the "first flat plate" of the present invention.

[0016] The frame body 22 is a flat plate, and the shape of the frame body 22 in plan view is a square. An opening is formed in the frame body 22. The opening penetrates the flat plate constituting the frame body 22 in the thickness direction (z-axis direction). The opening is a square in plan view. The shape of the opening is similar to the outer shape of the frame body 22, and the center of the frame body 22 and the center of the opening are the same. Adjacent pairs of corners C20 of the frame body 22 and corners C24 of the opening are in the same direction relative to this center. By providing such openings, the frame body 22 has four inner circumferential ends 221, 222, 223, and 224. The inner circumferential end 221 and the inner circumferential end 223 are parallel, the inner circumferential end 222 and the inner circumferential end 224 are parallel, and the inner circumferential ends 221 and 223 are perpendicular to the inner circumferential ends 222 and 224. One end of inner circumferential end 221 is connected to one end of inner circumferential end 222, the other end of inner circumferential end 222 is connected to one end of inner circumferential end 223, the other end of inner circumferential end 223 is connected to one end of inner circumferential end 224, and the other end of inner circumferential end 224 is connected to the other end of inner circumferential end 221. The connection of these inner circumferential ends forms corner C24 of the opening described above.

[0017] The central flat plate 21 is placed inside the opening of the frame body 22. In this case, the center of the opening and the center o21 of the central flat plate 21 coincide with each other. Since the area of ​​the central flat plate 21 is smaller than the area of ​​the opening of the frame body 22, even if the central flat plate 21 is placed inside the opening of the frame body 22, an opening remains between the outer peripheral edge of the central flat plate 21 and the frame body 22.

[0018] Each of the multiple connecting members 23 has a beam shape. The multiple connecting members 23 are disposed in an opening between the central flat plate 21 and the frame body. The multiple connecting members 23 are disposed along the outer periphery of the central flat plate 21 at intervals from one another.

[0019] With this configuration, the central flat plate 21 is supported via the multiple connecting members 23 in a state in which it can vibrate in a bending manner relative to the frame body 22 .

[0020] (More specific configuration of the connecting member 23) Each of the multiple connecting members 23 includes a first portion 231, a second portion 232, and a third portion 233. The first portion 231 has a shape extending along a radial direction r. As shown in FIG. 2(B), the radial direction r is a direction from the center o21 of the central plate 21 toward the outside. The second portion 232 has an arc shape extending along the outer periphery of the central plate 21. The third portion 233 has a shape extending along the radial direction r.

[0021] One end of the first portion 231 in the extending direction is connected to the outer circumferential end of the central flat plate 21. The other end of the first portion 231 in the extending direction is connected to approximately the center of the second portion 232 in the extending direction. Both ends of the second portion 232 in the extending direction are connected to different inner circumferential ends via the third portion 233.

[0022] Specifically, one end of one second portion 232 is connected to inner circumferential end 221, and the other end is connected to inner circumferential end 222. One end of one second portion 232 is connected to inner circumferential end 222, and the other end is connected to inner circumferential end 223. One end of one second portion 232 is connected to inner circumferential end 223, and the other end is connected to inner circumferential end 224. One end of one second portion 232 is connected to inner circumferential end 224, and the other end is connected to inner circumferential end 221.

[0023] With this configuration, the multiple connecting members 23 connect the central plate 21 and the frame body 22 so as to have an opening 241 configured to include an area on the central plate 21 side of the second portion 232, and an opening 242 in an area on the frame body 22 side of the second portion 232.

[0024] With this configuration, the opening 242 has a shape including the corner portion C24 of the opening, and a larger opening area than the conventional configuration can be realized without increasing the shape of the frame body 22. Specifically, as shown in FIG. 3, in the flat plate member 20P of the conventional configuration, the opening on the frame body 22P side from the second portion 232 is an arc shape along the second portion 232. In contrast, as shown in FIG. 2(B), in the flat plate member 20 of the present application, the distance (opening width) w242 between the second portion 232 and the corner portion C24 of the opening is larger than the width w232 of the second portion 232. Therefore, the area of ​​the opening 242 of the flat plate member 20 of the present application is larger than the area of ​​the opening 242P of the conventional flat plate member 20. Furthermore, the distance between the second portion 232 and the frame body 22 is larger than the distance between the second portion 232 and the frame body 22P of the conventional configuration, except for both ends in the extending direction of the second portion 232.

[0025] Therefore, the opening 242 is easy to form, and particularly when the opening 242 is formed by processing a single flat plate, and more particularly when the opening 242 is formed by etching a single metal plate, the opening 242 can be formed while preventing the width of the second portion 232 from narrowing. That is, in the conventional configuration, if an attempt is made to reliably form the opening 242P without changing the shape of the frame body 22P, as in the configuration of the present invention, the width of the second portion 232 will be narrowed. However, by forming the opening 242 as in the present invention, it is possible to prevent the width of the second portion 232 from narrowing.

[0026] This makes it easy for the flat plate member 20 to ensure the rigidity required for the connecting member 23, and makes it easy to achieve miniaturization. Note that the rigidity required for the connecting member 23 is, for example, a rigidity that prevents the connecting member 23 from breaking up to a predetermined condition when the fluid control device 10 including the flat plate member 20 is dropped.

[0027] It is preferable that the width w241 of the opening 241 (the distance between the central flat plate 21 and the second portion 232) is approximately the same as the width w232 of the second portion 232. This makes it possible to make the outer shape of the flat plate member 20 as small as possible while preventing the area of ​​the central flat plate 21 from becoming small, and also makes it possible to more reliably form the opening 241.

[0028] Moreover, it is preferable that the first portion 231 of each connecting member 23 overlaps with a straight line connecting the center o21 and the corner C24. That is, the multiple connecting members 23 are arranged at equal intervals along the outer periphery of the central flat plate 21. This allows the central flat plate 21 to be efficiently supported by the frame body 22. Also, in this configuration, the lengths of the third portions 233 connected to both ends of the second portions 232 can be made the same. This allows a support mechanism with good axial symmetry to be realized, and the central flat plate 21 can be supported while preventing vibration leakage to the frame body 22. For example, the vibration displacement of the frame body 22 can be suppressed to 10% or less of that of the central flat plate 21.

[0029] Furthermore, with this configuration, the distance from the connection position of the second portion 232 to the first portion 231 to one inner circumferential end of the frame body 22 is the same as the distance from the connection position of the first portion 231 to one inner circumferential end of the frame body 22. This makes it possible to realize a support mechanism with good axial symmetry, and to support the central plate 21 while preventing vibration leakage to the frame body 22. For example, the vibration displacement of the frame body 22 can be suppressed to 10% or less of the central plate 21.

[0030] In addition, in this configuration, the extension direction of the first portion 231 is perpendicular to the extension direction of the portion of the second portion 232 that is connected to the first portion 231. This allows the shape of the flat plate member 20 to be smaller than when the shape of the second portion 232 is the same but the first portion 231 and the second portion 232 are not perpendicular to each other.

[0031] In addition, in this configuration, the second portion 232 has a shape that follows the outer periphery of the central flat plate 21. This allows the shape of the flat plate member 20 to be smaller than other shapes, assuming that the length of the second portion 232 is the same.

[0032] (Configuration of the fluid control device 10) By using the actuator 11 having the above-mentioned configuration, a fluid control device 10 can be configured as shown in Fig. 1. The fluid control device 10 includes the actuator 11, a second flat plate 40, and a sidewall member 50.

[0033] The second flat plate 40 is disposed on the main surface 202 side of the central flat plate 21, the frame body 22, and the connecting member 23 of the actuator 11. The second flat plate 40 has a plurality of through holes 400. The plurality of through holes 400 are disposed at positions overlapping with the central flat plate 21 in a plan view.

[0034] The sidewall member 50 is annular and has a hollow 500, and is disposed between the flat plate member 20 of the actuator 11 and the second flat plate 40. The hollow 500 has substantially the same shape as the opening formed by the inner peripheral end of the frame body 22. The sidewall member 50 is connected to the frame body 22 and the second flat plate 40. As a result, the space surrounded by the actuator 11, the sidewall member 50, and the second flat plate 40 (the hollow 500 of the sidewall member 50) becomes a pump chamber. The pump chamber communicates with the external space on the second flat plate 40 side of the fluid control device 10 through a plurality of through holes 400. The pump chamber also communicates with the external space on the actuator 11 side of the fluid control device 10 through a plurality of openings 241, 242.

[0035] Second embodiment An actuator and a fluid control device according to a second embodiment of the present invention will be described with reference to the drawings. Fig. 4 is a plan view of the actuator according to the second embodiment.

[0036] 4, the actuator and fluid control device according to the second embodiment differs from the actuator 11 and fluid control device 10 according to the first embodiment in the configuration of the flat plate member 20A. Other configurations of the actuator and fluid control device according to the second embodiment are similar to those of the actuator 11 and fluid control device 10 according to the first embodiment, and a description of similar parts will be omitted.

[0037] The flat plate member 20A includes a plurality of connecting members 23A. Each of the plurality of connecting members 23A includes a first portion 231 and a second portion 232. In other words, the plurality of connecting members 23A does not include a third portion 233. That is, both ends in the extending direction of the second portion 232 are directly connected to different inner circumferential ends of the frame body 22, respectively.

[0038] With this configuration, the actuator according to the second embodiment can be made smaller in size than the actuator 11 according to the first embodiment while achieving the same effects as the actuator 11 according to the first embodiment.

[0039] (Third embodiment) An actuator and a fluid control device according to a third embodiment of the present invention will be described with reference to the drawings. Fig. 5 is a plan view of the actuator according to the third embodiment.

[0040] 5, the actuator and fluid control device according to the third embodiment differs from the actuator 11 and fluid control device 10 according to the first embodiment in the configuration of the flat plate member 20B. Other configurations of the actuator and fluid control device according to the third embodiment are similar to those of the actuator 11 and fluid control device 10 according to the first embodiment, and a description of similar parts will be omitted.

[0041] In flat plate member 20B, frame 22B is rectangular, and the opening formed thereby (the portion surrounded by inner circumferential ends 221, 222, 223, 224) is also rectangular. Specifically, length L2 in the direction parallel to inner circumferential ends 222, 224 is greater than length L1 in the direction parallel to inner circumferential ends 221, 223.

[0042] Even with this configuration, the actuator according to the third embodiment can achieve the same effects as the actuator 11 according to the first embodiment.

[0043] (Fourth embodiment) An actuator and a fluid control device according to a fourth embodiment of the present invention will be described with reference to the drawings. Fig. 6 is a plan view of the actuator according to the fourth embodiment.

[0044] 6, the actuator and fluid control device according to the fourth embodiment differs from the actuator and fluid control device according to the second embodiment in the configuration of the flat plate member 20C. Other configurations of the actuator and fluid control device according to the fourth embodiment are similar to those of the actuator and fluid control device according to the second embodiment, and a description of similar parts will be omitted.

[0045] In the flat plate member 20C, the frame 22C is a regular hexagon, and the opening formed thereby (the portion surrounded by the inner circumferential ends 221, 222, 223, 224, 225, and 226) is also a regular hexagon.

[0046] The three connecting members 23C are each connected to a different inner circumferential end of the frame body 22C. The second portion 232 of one connecting member 23C is connected to the inner circumferential end 221 and the inner circumferential end 226. The second portion 232 of one connecting member 23C is connected to the inner circumferential end 222 and the inner circumferential end 223. The second portion 232 of one connecting member 23C is connected to the inner circumferential end 224 and the inner circumferential end 225.

[0047] Even with such a configuration, the actuator according to the fourth embodiment can achieve the same effect as the actuator according to the second embodiment. That is, the frame body is not limited to a square, and may be another regular polygon. Furthermore, the frame body is not limited to a regular polygon, and may be any polygon. This configuration is also applied to a configuration in which the corners C20 are R-chamfered.

[0048] In the above embodiment, the connection between the central flat plate 21 and the first part of the connecting member, the connection between the first part and the second part, the connection between the second part and the third part, and the connection between the third part and the frame have corners. However, these connection parts may have a rounded chamfered shape.

[0049] In the above description, a configuration has been shown in which the side wall member 50 is connected to the main surface 202 side of the frame body. However, another fixing member may be connected to the main surface 201 side of the frame body, or both the main surface 202 side and the main surface 201 side may be connected to another fixing member.

[0050] Furthermore, the configurations of the above-described embodiments can be combined as appropriate, and effects according to each combination can be achieved. [Explanation of symbols]

[0051] 10: Fluid control device 11: Actuator 20: Flat plate member 20A: Flat plate member 20B: Flat plate member 20C: Flat plate member 21: Central plate 22, 22B, 22C, 22P: Frame 23, 23A, 23C: Connecting members 30: Drive body 40:Second plate 50: Side wall member 201, 202: Main surfaces 221, 222, 223, 224, 225, 226: Inner end 231: Part 1 232:Second part 233: Third part 241, 242, 242P: Opening 400:Through hole 500:Hollow

Claims

1. A frame having a polygonal opening; a first circular flat plate disposed inside the opening and having a driver attached thereto; a plurality of connecting members disposed between the first flat plate and the frame body inside the opening and connecting an outer peripheral edge of the first flat plate and the frame body so as to leave a portion of the opening; Equipped with The connecting member includes a first portion and a second portion; the first portion has a shape extending in a direction away from the first flat plate with the outer peripheral end of the first flat plate as one end, one end in the extending direction being connected to the outer peripheral end and the other end in the extending direction being connected to the second portion, The second portion has a shape extending in a direction different from that of the first portion, Both ends of the second portion in the extending direction are connected to inner circumferential ends of the frame body, The plurality of positions where the connecting member is connected to the frame body are disposed at equal intervals along the outer periphery of the first flat plate. Actuator.

2. adjacent positions in a direction along the outer periphery among the plurality of positions are connected to different sides of the inner periphery end. The actuator of claim 1 .

3. The first portion is disposed at a position overlapping a straight line connecting a center of the first flat plate and a corner of the frame body. The actuator of claim 1 .

4. The connecting member is a third portion different from the first portion and the second portion; The third portion has a shape extending in a direction different from that of the second portion, Both ends of the second portion in the extending direction are connected to an inner circumferential end of the frame body via the third portion. The actuator of claim 1 .

5. An actuator according to any one of claims 1 to 4; a second flat plate facing the first flat plate, the connecting member, and the frame body and having a through hole in a portion overlapping the first flat plate; a sidewall member that is connected to the second flat plate and the frame and that forms a pump chamber together with the first flat plate, the connecting member, the frame, and the second flat plate; A fluid control device comprising:

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