VALVE AND FLUID CONTROL DEVICE

Abstract

Valve, comprising: a first plate (23) having a first ventilation opening (43); a second plate (21) defining a valve chamber (40) connected to the first opening (43) between the first plate (23) and the second plate (21), the second plate (21) having a second vent opening (41) connected to the valve chamber (40) and not opposite the first vent opening (43); and a layer (24) arranged between the first plate (23) and the second plate (21), the layer (24) having a third ventilation opening (42) which is not opposite to the first opening (43) and which is opposite to the second ventilation opening (41), wherein the second plate (21) has an auxiliary opening (49) which overlaps the first vent opening (43) in a front view of a main surface of the second plate (21), the main surface facing the valve chamber (40), wherein on the first plate (23) there is provided a vibration adjusting plate (54, 454) in which an upper blower chamber (55) is formed, said upper blower chamber (55) being arranged to overlap all of the first vent openings (43) in the first plate (23), all of the second vent openings (41) in the second plate (21) and all of the third vent openings (42) in the layer (24).

Description

[0001] The present invention relates to a valve that allows fluid to flow in one direction and a fluid control device incorporating the valve.

[0002] Various types of fluid control devices that control the flow of fluid have been disclosed. For example, WO 2011 / 040320 A discloses a piezoelectric microblower including a vibrating plate, a piezoelectric element that generates bending vibrations of the vibrating plate, and a top plate with a plurality of openings. This piezoelectric microblower generates bending vibrations of the vibrating plate using the piezoelectric element, thereby drawing in ambient air and expelling the air to the outside through the openings.

[0003] Since the piezoelectric micro blower includes a plurality of openings, noise generated near the openings (wind noise) can be reduced.

[0004] Similar micro blowers with a vibration membrane and a piezo element are shown in the documents WO 2010 / 139 918 A1, US 2013 / 0 071 269 A1 and US 4 164 238 B, the first of which, WO 2010 / 139 918 A1, shows two plates placed one above the other, between which a valve chamber is defined, the two plates each having ventilation openings and a layer being applied to one of the plates.

[0005] Furthermore, document WO 2010 / 139 918 A1 shows a pump with a diaphragm valve comprising two plates defining a chamber between them in which a diaphragm is arranged. The two plates are provided with hole patterns that are not aligned with one another, with the diaphragm located between them also having a hole pattern that matches the hole pattern of the plate on the pressure side. Furthermore, document US 2009 / 0 232 682 A1 shows a piezoelectric microblower whose blower chamber is defined by two plates, one of which can be deflected or set into vibration by a piezo element, while the other is provided with an outlet hole. A third plate is arranged above this perforated plate, which has an outlet hole aligned with the perforated plate and can draw air from the radial sides.

[0006] Although the piezoelectric microblower according to WO 2011 / 040 320 A includes a plurality of openings, a maximum discharge flow rate thereof is only 1.1 (L / min) (cf. Fig. 9 of WO 2011 / 040320 A). Thus, the piezoelectric microblower has a low discharge flow rate and pressure.

[0007] Accordingly, if a backflow prevention valve is mounted on the openings of the piezoelectric microblower, the valve must have a low flow resistance so that the air expelled from the openings flows in one direction. This occurs because the air discharged through the openings of the piezoelectric microblower and expelled from the valve through passages in the valve has a reduced flow rate and pressure due to the flow resistance of the valve.

[0008] An object of the present invention is to provide a valve and a fluid control device that allows a gas expelled from a blower to pass therethrough while minimizing reductions in the flow rate and pressure of the gas.

[0009] To solve the above-mentioned problem, the present invention provides a valve according to claim 1 and a fluid control device with such a valve according to claim 7. Preferred embodiments of the invention are the subject of the dependent claims.

[0010] A valve according to the present invention includes a first plate, a second plate, and a layer. The first plate has a first vent opening. The second plate defines a valve chamber connected to the first opening between the second plate and the first plate. The second plate has a second vent opening connected to the valve chamber and not opposed to the first vent opening. The layer is disposed between the first plate and the second plate. The layer has a third vent opening not opposed to the first vent opening and opposed to the second vent opening.

[0011] The second plate has an auxiliary opening that overlaps the first vent opening in a front view of a main surface of the second plate, the main surface facing the valve chamber.

[0012] In this design, the first vent is connected, for example, to an exhaust port of a fan, and the second vent is open, for example, to the outside.

[0013] With this structure, when the fan is operating, a portion of the layer facing the auxiliary opening is deformed into an auxiliary opening due to gas discharged into the valve chamber through the first vent. Accordingly, the gap between the first plate and that portion of the layer increases. As a result, the flow resistance of the valve is lower, and the gas flow rate and pressure are higher than those in the case where the second plate does not have the auxiliary opening.

[0014] Thus, the valve having the structure described above allows the gas discharged from the blower to pass therethrough while minimizing reductions in the flow rate and pressure of the gas.

[0015] In the valve according to the present invention, a center axis of the auxiliary opening preferably coincides with a center axis of the first ventilation opening.

[0016] According to this structure, when viewed from the front, the main surface of the second plate overlaps the valve chamber, the area where the auxiliary port overlaps the first vent hole is larger than that in the case where the center axes are not aligned. Therefore, with this structure, the flow passage resistance of the valve is reduced, and the flow rate and pressure of the gas are increased.

[0017] In the valve according to the present invention, a plurality of auxiliary openings are preferably provided, and the second plate includes a crosspiece part arranged between the auxiliary openings.

[0018] According to this structure, since the crosspiece portion is provided between the auxiliary openings, the layer comes into contact with the crosspiece portion when the layer is deformed. Thus, the crosspiece portion prevents deformation of the layer, thereby preventing damage to the layer. As a result, the durability of the valve is increased.

[0019] In the valve according to the present invention, a diameter of the auxiliary opening is preferably larger than a diameter of the first vent opening.

[0020] When the valve has such a structure, the flow rate of the gas is higher than that in the case where the diameter of the auxiliary opening is smaller than the diameter of the first vent opening.

[0021] If rh is a radius of the first vent, Rs is a radius of the auxiliary vent, r1 and r2 are radii of two second vents located on both sides of the auxiliary vent, and a is a distance between center points of the two second vents located on both sides of the auxiliary vent, the following expression is satisfied: {a−(r1+r2)} / 2>Rs≥rh.

[0022] In the valve according to the present invention, a diameter of the auxiliary opening is preferably smaller than a diameter of the first vent opening.

[0023] When the valve has such a structure, the pressure of the gas is higher than that in the case where the diameter of the auxiliary opening is larger than a diameter of the first vent opening.

[0024] A fluid control device according to the present invention includes the above-described valve according to the present invention and a blower. The blower includes a blower chamber connected to the first vent, a vibrating body facing the blower chamber, and a drive body that generates bending vibration of the vibrating body.

[0025] The fluid control device according to the present invention includes the above-described valve according to the present invention, and therefore has an operation similar to that of the valve.

[0026] The vibrating body includes a peripheral region and a central region. The peripheral region extends from the outermost node of the pressure vibration generated in the blower chamber by the bending vibration of the vibrating body to the outer periphery of the blower chamber. The central region is located within the peripheral region. The peripheral region is a region where bending vibration of the peripheral region is suppressed.

[0027] The present invention allows a gas discharged from the blower to flow while minimizing reductions in the flow rate and pressure of the gas. Fig. 1 is an external perspective view of a fluid control device 111 according to a first embodiment of the present invention, viewed from above the fluid control device 111. Fig. 2 is an external perspective view of the Fig. 1, viewed from below the fluid control device 111. Fig. 3 is an exploded perspective view of the Fig. 1 illustrated fluid control device 111. Fig. 4 is a front view of a central part of a top plate 21 illustrated in Fig. 3. Fig. Figure 5 is a front view of a central portion of a layer 24 illustrated in Fig. 3. Fig. Figure 6 is a front view of a central part of a combination of the layer 24 and a bottom plate 23 illustrated in Fig. 3. Fig. Fig. 7 is an enlarged front view of a communication port 43, ejection ports 41, and an auxiliary port 49 illustrated in Fig. 3. Fig. 8 is a side sectional view of the fluid control device 111 illustrated in Fig. 1. Fig. 9 shows side sectional views illustrating the air flow in the fluid control device 111 while a Fig. 1 illustrated blower section 13 is in operation. Fig. Fig. 10 is an enlarged sectional view showing the air flow around an auxiliary opening 49 at the time of Fig. 9(B) illustrates. Fig. 11 is a front view of a central part of a top plate 221 included in a fluid control device 211 according to a second embodiment of the present invention. Fig. 12 is an enlarged sectional view illustrating the air flow around an auxiliary opening 249 while a Fig. 11 illustrated fluid control device 211 is in operation. Fig. 13 is a front view of a central part of a top plate 321 included in a valve portion 321 of a fluid control device 311 according to a third embodiment of the present invention. Fig. 14 is a graph showing the relationship between the discharge flow rate of the air discharged from the discharge ports and the driving voltage in a plurality of fluid control devices 111 having the auxiliary ports 49 of different diameters and a fluid control device according to a comparative example. Fig. 15 is a graph showing the relationship between the discharge pressure of the air discharged from the discharge ports 41 and the driving voltage in the fluid control device 111 having the auxiliary ports 49 of different diameters and the fluid control device according to the comparative example. Fig. 16 is a graph showing the relationship between the discharge flow rate of the air discharged from the discharge ports and the driving voltage in the fluid control device 211 and the fluid control device according to the comparative example. Fig. 17 is a graph showing the relationship between the discharge pressure of the air discharged from the discharge ports 41 and the drive voltage in the fluid control device 211 and the fluid control device according to the comparative example. Fig. 18 is a graph showing variations in displacement of the bottom plate 23, a piezoelectric element 33, and the layer 24 included in the fluid control device 111. Fig. 19 is a graph showing variations in displacement of the bottom plate 23, a piezoelectric element 33, and the layer 24 included in the fluid control device 311. Fig. Figure 20 is a side sectional view of a fluid control device 411 according to another embodiment of the present invention. Description of Embodiments

[0028] A fluid control device 111 according to a first embodiment of the present invention will now be described.

[0029] Fig. 1 is an external perspective view of the fluid control device 111 according to the first embodiment of the present invention, viewed from above the fluid control device 111. Fig. 2 is an external perspective view of the Fig. 1, viewed from below the fluid control device 111. Fig. 3 is an exploded perspective view of the Fig. 1 illustrated fluid control device 111. Fig. 4 is a front view of a central part of a top plate 21 illustrated in Fig. 3. Fig. Figure 5 is a front view of a central portion of a layer 24 illustrated in Fig. 3. Fig. Figure 6 is a front view of a central part of a combination of the layer 24 and a bottom plate 23 illustrated in Fig. 3. Fig. Fig. 7 is an enlarged front view of a communication port 43, ejection ports 41, and an auxiliary port 49 illustrated in Fig. 3. Fig. 8 is a sectional view taken along line SS in Fig. 1.

[0030] As in the Fig. 1 and Fig. 2, the fluid control device 111 includes a valve section 12, a blower section 13, and a controller 14 (see Fig. 8). As in the Fig. 1 and Fig. 3, the valve section 12 is arranged at the top of the fluid control device 111. As shown in the Fig. 2 and Fig. 3, the blower section 13 is located at the bottom of the fluid control device 111. The valve section 12 and the blower section 13 are stacked and bonded together.

[0031] The valve portion 12 allows fluid to flow in one direction. The valve portion 12 has the shape of a cylindrical container with a valve chamber provided therein. As shown in the Fig. 1 and Fig. 3, the valve section 12 includes the top plate 21, a side wall plate 22, the bottom plate 23, and the layer 24.

[0032] The bottom plate 23 corresponds to an example of a first plate according to the present invention. The top plate 21 corresponds to an example of a second plate according to the present invention. The bottom plate 23 also corresponds to an example of a vibrating body according to the present invention.

[0033] The top plate 21, the side wall plate 22, and the bottom plate 23 are made of metal. For example, the top plate 21, the side wall plate 22, and the bottom plate 23 are made of stainless steel (SUS). The layer 24 is made of a synthetic resin. For example, the layer 24 is made of a translucent polyimide.

[0034] The top plate 21 is arranged on top of the valve section 12. The side wall plate 22 is arranged between the top plate 21 and the bottom plate 23. The bottom plate 23 is arranged at the bottom of the valve section 12. The top plate 21, the side wall plate 22, and the bottom plate 23 are stacked and bonded together. The layer 24 is arranged in the valve section 12, that is, in the valve chamber 40.

[0035] The top plate 21 is disc-shaped when viewed from above. The side wall plate 22 is ring-shaped when viewed from above. The bottom plate 23 is disc-shaped when viewed from above. The top plate 21, the side wall plate 22, and the bottom plate 23 have the same outer diameter.

[0036] The valve chamber 40 is provided in the center of the sidewall plate 22 and has a predetermined opening diameter. The layer 24 is substantially disc-shaped when viewed from above. The layer 24 has a smaller thickness than that of the sidewall plate 22.

[0037] In the present embodiment, the thickness of the side wall plate 22 (height of the valve chamber 40) is 40 μm or more and 50 μm or less, and the thickness of the layer 24 is 5 μm or more and 10 μm or less. The layer 24 is extremely lightweight to be vertically movable in the valve chamber 40 while receiving the air discharged from the blower section.

[0038] The outer diameter of layer 24 is substantially equal to the opening diameter of valve chamber 40 in sidewall plate 22, but is slightly smaller than the opening diameter so that a gap is provided. Projections 25 are provided on the outer periphery of layer 24 (see FIG. Fig. 3).

[0039] The side wall plate 22 has cut-out portions 26 in the inner circumference thereof (cf. Fig. 3). The projections 25 are arranged in the respective cutout portions 26 with small gaps therebetween. Thus, the layer 24 is held in the valve chamber 40 in a non-rotatable and vertically movable manner.

[0040] A plurality of discharge ports 41 and a plurality of auxiliary ports 49 arranged in a predetermined pattern are formed in a central region of the top plate 21. A plurality of communication ports 43 arranged in a predetermined pattern are formed in a central region of the bottom plate 23. A plurality of layer ports 42 arranged in a predetermined pattern are formed in a central region of the layer 24. Thus, the valve chamber 40 communicates with the outside through the discharge ports 41 and with the blower chamber 45 through the communication ports 43.

[0041] The discharge ports 41 and the communication ports 43 are arranged so as not to oppose each other. The auxiliary ports 49 and the communication ports 43 are arranged so as to oppose each other. Each auxiliary port 49 overlaps the corresponding communication port 43 when viewed from a front view of the main surface of the top plate 21 facing the valve chamber 40. The center axis of each auxiliary port 49 coincides with the center axis of the corresponding communication port 43.

[0042] The layer openings 42 and the ejection openings 41 are arranged to oppose each other. The layer openings 42 and the auxiliary openings 49 are arranged to not oppose each other. The layer openings 42 and the communication openings 43 are arranged to not oppose each other.

[0043] The communication openings 43 correspond to an example of a first vent according to the present invention. The discharge openings 41 correspond to an example of a second vent according to the present invention. The layer openings 42 correspond to an example of a third vent according to the present invention.

[0044] The diameter of the auxiliary openings 49 is preferably greater than or equal to the diameter of the communication openings 43. More specifically, with reference to Fig. 7, when the radius of the communication port 43 is rh, the radius of the auxiliary port 49 is Rs, the radii of the two ejection ports 41 on both sides of the auxiliary port 49 are r1 and r2, and the distance between the center points of the two ejection ports 41 on both sides of the auxiliary port 49 is a, the following relationship is satisfied: {a-(r1+r2)} / 2 > Rs ≥ rh.

[0045] The blower section 13 is a pump that includes a diaphragm 36 that is bent when a voltage is applied to the piezoelectric element 33. As shown in Fig. 2 and Fig. 3, the blower section 13 has the shape of a cylindrical container with a blower chamber 45 provided therein.

[0046] The fan section 13 includes a vibration adjustment plate 54, a side wall plate 31, a bottom plate 32, and a piezoelectric element 33. The vibration adjustment plate 54, the side wall plate 31, the bottom plate 32, and the piezoelectric element 33 are made of metal. For example, the vibration adjustment plate 54, the side wall plate 31, the bottom plate 32, and the piezoelectric element 33 are made of stainless steel.

[0047] The piezoelectric element 33 corresponds to an example of a drive body according to the present invention.

[0048] The side wall plate 31 is arranged between the bottom plate 23 and the bottom plate 32. The bottom plate 32 is arranged between the side wall plate 31 and the piezoelectric element 33. The piezoelectric element 33 is arranged at the bottom of the fan section 13. The side wall plate 31, the bottom plate 32, and the piezoelectric element 33 are stacked on and bonded to the bottom surface of the bottom plate 23. The side wall plate 31, the bottom plate 32, and the piezoelectric element 33 are stacked and bonded together.

[0049] The vibration adjustment plate 54 is provided to adjust the vibration range of the bottom plate 23. Specifically, the vibration adjustment plate 54 is bonded between the bottom plate 23 and the side wall plate 31. The vibration adjustment plate 54 is annular when viewed from above.

[0050] An upper blower chamber 55 with a predetermined opening diameter is formed in a central portion of the vibration adjusting plate 54. The opening diameter of the upper blower chamber 55 is smaller than that of a lower blower chamber 48. The upper blower chamber 55 and the lower blower chamber 48 form the blower chamber 45. The vibration adjusting plate 54 and the side wall plate 31 have the same outer diameter.

[0051] Since the vibration adjustment plate 54 is provided on the bottom plate 23, the bending strength is locally increased in the area around the outer peripheral portion of the bottom plate 23. Accordingly, the bottom plate 23 can be set so that a central portion thereof facing the upper blower chamber 55 vibrates, and the outer peripheral portion thereof hardly vibrates.

[0052] Thus, the range in which the bottom plate 23 vibrates can be set in accordance with the opening diameter of the upper blower chamber 55 in the vibration adjustment plate 54. Accordingly, the vibration range and the body resonance frequency can be easily adjusted without, for example, changing the thickness or outer diameter of the bottom plate 23.

[0053] The vibration of the central portion of the bottom plate 23 mainly contributes to the vibration of the fluid in the layer 24. Therefore, even if the outer peripheral portion of the bottom plate 23 does not vibrate, the sensitivity and discharge flow rate of the valve portion 12 can be sufficiently increased.

[0054] The side wall plate 31 is annular when viewed from above. The lower fan chamber 48, which has a predetermined opening diameter, is formed in a central region of the side wall plate 31. The bottom plate 32 includes an outer peripheral portion 34. The outer peripheral portion 34 is annular when viewed from above and has an opening with a predetermined opening diameter in a central region of a main surface when viewed from above.

[0055] The side wall plate 31 and the outer peripheral portion 34 of the bottom plate 32 have the same outer diameter and the same opening diameter, and are stacked and bonded together. The outer diameter of the side wall plate 31 and the bottom plate 32 is smaller than the outer diameter of the valve portion 12 by a predetermined amount.

[0056] The bottom plate 32 includes a plurality of jet parts 35 and the diaphragm 36 in addition to the outer peripheral portion 34. The diaphragm 36 is disc-shaped when viewed from above and is arranged in the opening of the outer peripheral portion 34 so as to provide a gap between the diaphragm 36 and the outer peripheral portion 34. The jet parts 35 are arranged in the gap between the outer peripheral portion 34 and the diaphragm 36. The jet parts 35 extend in the circumferential direction of the bottom plate 32 to connect the diaphragm 36 and the outer peripheral portion 34 to each other.

[0057] Thus, the diaphragm 36 is suspended in the air by the jet members 35 and is vertically movable in the thickness direction. The openings between the outer peripheral portion 34 and the diaphragm 36 serve as intake openings 46.

[0058] The piezoelectric element 33 is disc-shaped when viewed from above and has a smaller radius than that of the diaphragm 36. The piezoelectric element 33 is bonded to the bottom surface of the diaphragm 36. The piezoelectric element 33 is made, for example, of a lead titanate zirconate ceramic.

[0059] Electrodes (not shown) are formed on both main surfaces of the piezoelectric element 33, and the controller 14 applies a driving voltage to the piezoelectric element 33 via these electrodes. The piezoelectric element 33 has piezoelectric properties and expands and contracts in a surface direction in accordance with the driving voltage applied thereto.

[0060] When a driving voltage is applied to the piezoelectric element 33, the piezoelectric element 33 expands and contracts in a plane direction, generating concentric bending vibrations of the diaphragm 36. This bending vibration causes the beam members 35, which elastically support the diaphragm 36, to vibrate, and accordingly, the diaphragm 36 vibrates in the vertical direction. Thus, the piezoelectric element 33 and the diaphragm 36 form a piezoelectric actuator 37 and vibrate together.

[0061] The controller 14 is implemented, for example, as a microcomputer. In the present embodiment, the controller 14 adjusts the drive frequency of the piezoelectric element 33 to the resonance frequency of the blower chamber 45. The resonance frequency of the blower chamber 45 is a frequency at which the pressure vibration generated in the center of the blower chamber 45 and the pressure vibration generated in the center of the blower chamber 45, reflected by the outer peripheral portion and returned to the center of the blower chamber 45, resonate.

[0062] When such adjustment is performed, a region around the center in the surface direction serves as an antinode of the bending vibration, and a region near the outer periphery in the surface direction serves as a node of the bending vibration. Thus, a pressure distribution in the form of a standing wave is formed in the surface direction in the blower chamber 45.

[0063] Thus, the pressure variation of the fluid is large in a region near the communication ports 43 facing the central portion of the blower chamber 45 in the surface direction, and is extremely small in a region around the suction ports 46 facing the outer peripheral portion of the blower chamber 45 in the surface direction.

[0064] Therefore, when the suction ports 46 communicate with the outer peripheral portion of the blower chamber 45 in the surface direction, the pressure loss through the suction ports 46 can be substantially eliminated even if the suction ports 46 are not provided with a valve or the like. Therefore, the suction ports 46 can be formed in any shape or size, and the flow rate of the fluid can be increased.

[0065] Now, the flow of fluid in the fluid control device 111 while the blower section 13 is in operation will be described.

[0066] Fig. 9 shows side sectional views illustrating the air flow in the fluid control device 111 during the Fig. 1 illustrated blower section 13 is in operation. Fig. Fig. 10 is an enlarged sectional view showing the air flow around an auxiliary opening 49 at the time of Fig. 9(B). The sectional view of Fig. 10 is along the line TT in Fig. 1. The arrows in the Fig. 9 and Fig. 10 indicate the air flow.

[0067] When the controller 14 applies an AC drive voltage across the electrodes on both main surfaces of the piezoelectric element 33 in the Fig. 8, the piezoelectric element 33 expands and contracts, thereby generating a concentric bending vibration of the membrane 36. Accordingly, as shown in the Fig. 9(A) and Fig. As illustrated in Fig. 9(B), the piezoelectric actuator 37 is bent and the volume of the blower chamber changes periodically.

[0068] If the membrane 36 as in Fig. 9(A), the pressure in the blower chamber 45 decreases, and the layer 24 is drawn toward the bottom plate 23 and comes into contact with the bottom plate 23 in the blower chamber 45. Accordingly, the communication ports 43 are closed, and the airflow from the valve chamber 40 to the communication ports 43 is blocked. Accordingly, outside air is sucked into the blower chamber 45 through the intake ports 46.

[0069] If the membrane 36 as in Fig. 9(B), the pressure in the blower chamber 45 increases, and air is discharged from the communication ports 43 toward the valve chamber 40. The layer 24 is pushed upward by the discharged air and comes into contact with the top plate 21. Accordingly, the communication ports 43 are opened so that the air flow is not blocked, and the air flows into the valve chamber 40 through the communication ports 43. The air in the valve chamber 40 is discharged to the outside through the discharge ports 41 in the valve portion 12.

[0070] The vibration of the piezoelectric actuator 37 is transmitted directly from the fan section 13 to the valve section 12, or indirectly through the air to the valve section. As a result, the top plate 21 vibrates.

[0071] Accordingly, the top plate 21 is also elastically deformed to move vertically in the thickness direction. As shown in Fig. As illustrated in Fig. 9(B), when the piezoelectric actuator 37 is bent upward and the air in the blower chamber 45 is discharged into the valve chamber through the communication holes 43, the top plate 21 is also bent upward, similar to the piezoelectric actuator 37. As a result, the volume of the valve chamber 40 increases.

[0072] As in Fig. 9(A), when the piezoelectric actuator 37 is bent upward, the top plate 21 is bent downward as a rebound from the Fig. 9(B). As a result, the volume of the valve chamber 40 decreases.

[0073] Accordingly, the distance by which the layer 24 is pulled downward and the time required for the layer 24 to move downward into the valve chamber 40 are reduced. This allows the layer 24 to move in accordance with the air pressure variation and increases the sensitivity of the valve portion.

[0074] The bottom plate 23 may be vibrated due to the vibration of the piezoelectric actuator 37, which is transmitted directly from the fan section 13 or indirectly transmitted through the air.

[0075] As in Fig. 10, while the blower section 13 is in operation, a part of the layer 24 facing each auxiliary opening 49 is deformed into an auxiliary opening 49 due to the air flowing through the corresponding communication opening 43 at the time of Fig. 9(B) into the valve chamber 40. Accordingly, the gap h1 between the bottom plate 23 and the layer 24 increases. As a result, the flow passage resistance of the valve portion 12 is lower, and the flow rate and pressure of the air are higher than those in the case where the top plate 21 does not have the auxiliary openings 49.

[0076] Thus, the fluid control device 111 and the valve portion 12 allow the air discharged from the blower portion 13 to pass therethrough while keeping reductions in the flow rate and pressure of the air small.

[0077] In the valve section 12, the center axis of each auxiliary port 49 coincides with the center axis of the corresponding communication port 43. Accordingly, in a front view of the main surface of the top plate 21 facing the valve chamber 40, the area in which each auxiliary port 49 overlaps the corresponding communication port 43 is larger than that in the case where the center axes do not coincide. Therefore, the flow passage resistance of the valve section 12 is reduced, and the flow rate and pressure of the air are increased.

[0078] In the valve section 12, the diameter of the auxiliary openings 49 is greater than or equal to the diameter of the communication openings 43.

[0079] While the blower section 13 is operating, parts of the layer facing the auxiliary openings 49 are deformed into the auxiliary openings 49 due to the air discharged into the valve chamber 40 through the corresponding communication holes 43. As a result, the flow passage resistance of the valve section 12 can be kept small.

[0080] As in the Fig. 3 to 7, the diameter of the auxiliary openings 49 is equal to or greater than the diameter of the communication openings 43. Therefore, the manufacturer can easily visually determine whether or not the layer 24 has processing damage or has been damaged or contaminated in the manufacturing process by the auxiliary openings 49 in the top plate 21.

[0081] Since the diameter of the auxiliary holes 49 is equal to or greater than the diameter of the communication holes 43 and the layer 24 is translucent, the manufacturer can position the top plate 21, the layer 24, and the bottom plate 23 while observing the auxiliary holes 49 in the top plate 21 during the manufacturing process. Specifically, the manufacturer can easily arrange the communication holes 43, the layer holes 42, and the auxiliary holes 49 without displacement during the assembly process. Thus, the manufacturer can easily assemble the fluid control device 111.

[0082] A fluid control device 211 according to a second embodiment of the present invention will now be described.

[0083] Fig. 11 is a front view of a central part of a top plate 221 included in the fluid control device 211 according to the second embodiment of the present invention. Fig. 12 is an enlarged sectional view illustrating the air flow around an auxiliary opening 249 while a Fig. 11 illustrated fluid control device 211 is in operation. The arrow in Fig. 12 indicates the air flow.

[0084] The fluid control device 211 differs from the fluid control device 111 in that the top plate 221 has crosspiece portions 248 that partition the auxiliary openings 249. Other structures are the same as those of the fluid control device 111, and their description is omitted.

[0085] Also, in this structure, as in Fig. 12 illustrates that while the blower section 13 is operating, a part of the layer 24 facing each auxiliary opening 249 is deformed into the auxiliary opening 249 due to the air discharged into the valve chamber 40 through the corresponding communication port 43. Accordingly, the gap h2 between the bottom plate 23 and the layer 24 increases. As a result, the flow passage resistance of the valve section 212 is lower, and the flow rate and pressure of the air are higher than those in the case where the top plate 221 does not have the auxiliary openings 249.

[0086] Thus, the fluid control device 211 and the valve portion 212 allow the air discharged from the blower portion 13 to pass therethrough while keeping reductions in the flow rate and pressure of the air small.

[0087] In the fluid control device 111 described above, when the amount of air discharged through the communication holes 43 into the valve chamber 40 suddenly increases, there is a risk that parts of the layer 24 will be severely deformed into the auxiliary holes 49 and damaged (see FIG. Fig. 10).

[0088] In this construction, the layer 24 comes into contact with crosspiece parts 248, as in Fig. 12, the crosspiece portions 248 are provided between the auxiliary openings 49. Thus, the crosspiece portions 248 prevent deformation of the layer 24, thereby preventing damage to the layer 24. As a result, the bending strength of the valve portion 212 and the fluid control device 211 is increased.

[0089] A fluid control device 311 according to a third embodiment of the present invention will now be described.

[0090] Fig. 13 is a front view of a central part of a top plate 321 included in a valve section 321 of the fluid control device 311 according to the third embodiment of the present invention. The fluid control device 311 differs from the fluid control device 111 in that the diameter of the auxiliary holes 49 is smaller than the diameter of the communication holes 43. Other structures are the same as those of the fluid control device 111, and thus, a description thereof is omitted.

[0091] Also, in this structure, while the blower section 13 is operating, a part of the layer 24 facing each auxiliary opening 349 is deformed into the auxiliary opening 349 due to the air discharged into the valve chamber 40 through the corresponding communication hole 43. Accordingly, the gap between the bottom plate 23 and the layer 24 increases. As a result, the flow passage resistance of the valve section 212 is lower, and the flow rate and pressure of the air are higher than those in the case where the top plate 321 does not have the auxiliary openings 349.

[0092] Thus, the fluid control device 311 and the valve portion 312 allow the air discharged from the blower portion 13 to pass therethrough while keeping reductions in the flow rate and pressure of the air small.

[0093] The discharge performances of the fluid control device 111 and a fluid control device according to a comparative example while the blower section 13 is operating are compared. The fluid control device according to a comparative example differs from the fluid control device 111 in that the top plate 21 does not have the auxiliary openings 49. Other structures are the same as those of the fluid control device 111, and thus, descriptions thereof are omitted.

[0094] Fig. 14 is a graph showing the relationship between the discharge flow rate of the air discharged from the discharge ports and the driving voltage in three fluid control devices 111 having the auxiliary ports 49 of different diameters and a fluid control device according to a comparative example. Fig. 15 is a graph showing the relationship between the discharge pressure of the air discharged from the discharge ports 41 and the drive voltage in the three fluid control devices 111 having the auxiliary ports 49 of different diameters and the fluid control device according to the comparative example.

[0095] Fig. 14 and Fig. 15 shows the result of the experiment conducted on three fluid control devices 111 having the auxiliary orifices 49 of different diameters and the fluid control device according to the comparative example. In the experiment, a drive voltage with a predetermined frequency (for example, 17 kHz) was applied to the piezoelectric element 33 of each fluid control device, and the discharge flow rate and discharge pressure of the air discharged from the discharge orifices 41 were measured.

[0096] In the experiment, the diameters of the auxiliary openings 49 in the three fluid control devices 111 were 0.4 µm, 0.8 µm, and 1.0 µm. The diameter of the communication openings 43 in the three fluid control devices 111 and the fluid control device of the comparative example was 0.8 µm.

[0097] As can be seen from the Fig. 14 and Fig. 15, the result of the experiment shows that the discharge flow rate and discharge pressure of the fluid control devices 111 were larger than those of the fluid control device according to the comparative example.

[0098] The possible reason for this result is that the flow passage resistance of the valve section 12 is reduced due to the auxiliary openings 49 overlapping the communication openings 43.

[0099] Thus, the fluid control device 111 and the valve portion 12 allow the air discharged from the blower portion 13 to pass therethrough while keeping reductions in flow rate and air pressure small.

[0100] As in Fig. As illustrated in Figure 14, the experimental result also shows that the discharge flow rate increases as the area of the auxiliary openings 49 overlapping the communication openings 43 increases. Specifically, the discharge flow rate is high when the diameter of the discharge flow rate is larger than the diameter of the communication openings 43.

[0101] As in Fig. As illustrated in Figure 15, the experimental result also shows that the discharge pressure decreases as the area of the auxiliary holes 49 overlapping the communication holes 43 increases. Specifically, the discharge pressure is high when the diameter of the discharge flow rate is smaller than the diameter of the communication holes 43.

[0102] Accordingly, in the valve portion 12 according to the present embodiment, the discharge pressure or the discharge flow rate can be further increased by adjusting the area of the discharge flow rate without increasing the drive voltage (without increasing the power consumption).

[0103] The discharge performances of the fluid control device 211 and the fluid control device according to the comparative example, which does not have the auxiliary openings, while the blower section is in operation are compared.

[0104] Fig. 16 is a graph showing the relationship between the discharge flow rate of the air discharged from the discharge ports and the driving voltage in the fluid control device 211 and the fluid control device according to the comparative example. Fig. 17 is a graph showing the relationship between the discharge pressure of the air discharged from the discharge ports 41 and the drive voltage in the fluid control device 211 and the fluid control device according to the comparative example.

[0105] Fig. 16 and Fig. 17 shows the result of the experiment in which a driving voltage having a predetermined frequency (for example, 17 kHz) was applied to the piezoelectric element 33 of each of the fluid control devices 211 and the fluid control device of the comparative example, and in which the ejection flow rate and ejection pressure of the air ejected from the ejection ports 41 were measured.

[0106] In the experiment, the diameter of each auxiliary opening 249 in the fluid control device 211 was 0.2 µm. The diameter of the communication openings 43 in the fluid control device 211 and the fluid control device of the comparative example was 0.8 µm.

[0107] As can be seen from the Fig. 16 and Fig. 17, the result of the experiment shows that the discharge flow rate and discharge pressure of the fluid control devices 211 are larger than those of the fluid control device according to the comparative example.

[0108] The possible reason for this result is that the flow passage resistance of the valve portion 212 is reduced due to the auxiliary openings 249 overlapping the communication openings 43.

[0109] Thus, the fluid control device 211 and the valve portion 212 allow the air discharged from the blower portion 13 to pass therethrough while keeping reductions in flow rate and air pressure small.

[0110] Furthermore, as can be seen from the Fig. 11 and Fig. As can be seen from Figure 12, the crosspiece parts 248 prevent deformation of the layer 24, thereby preventing damage to the layer 24. As a result, the bending strength of the valve portion 212 and the fluid control device 211 can be increased.

[0111] The displacement of the layer 24 included in the fluid control device 111 and the displacement of the layer 24 included in the fluid control device 311 while the fan section 13 is in operation are compared.

[0112] Fig. 18 is a graph showing variations in displacement of the bottom plate 23, a piezoelectric element 33, and the layer 24 included in the fluid control device 111. Fig. 19 is a graph showing variations in displacement of the bottom plate 23, a piezoelectric element 33, and the layer 24 included in the fluid control device 311.

[0113] In the Fig. 18 and Fig. 19, the displacements of the bottom plate 23, the piezoelectric element 33, and the layer 24 are measured using a laser Doppler vibrometer. The laser Doppler vibrometer can be used to measure the displacement of the layer 24 by irradiating the main surface of the layer 24 facing the valve chamber 40 with a laser beam through the auxiliary openings 49 and 349. The laser Doppler vibrometer can also be used to measure the displacement of the bottom plate 23 by irradiating the main surface of the bottom plate 23 facing the valve chamber 40 with a laser beam through the ejection openings 41. The laser Doppler vibrometer can also be used to measure the displacement of the piezoelectric element 33 by irradiating the main surface of the piezoelectric element 33 facing away from the blower chamber 45 with a laser beam.

[0114] As from Fig. 18, the result of the experiment shows that, in the fluid control device 111, a part of the layer 24 facing each auxiliary opening 49 is deformed to a large extent into the auxiliary opening 49 due to the air discharged into the valve chamber 40 through the corresponding communication opening 43.

[0115] On the other hand, as in Fig. 19 illustrates, in the fluid control device 311, a part of the layer 24 facing each auxiliary opening 349 is deformed to a small extent into the auxiliary opening 349 due to the air discharged into the valve chamber 40 through the corresponding communication opening 43.

[0116] Thus, it has become clear that the amount of deformation is larger when the auxiliary openings 49 having a diameter equal to or greater than the diameter of the communication openings 43 are formed than when the auxiliary openings 349 having a diameter smaller than the communication openings 43 are formed. In other words, the flow passage resistance of the valve section 12 with the auxiliary openings 49 is lower than the flow passage resistance of the valve section 312 with the auxiliary openings 349.

[0117] Therefore, it is conceivable that the auxiliary openings 49 have a diameter greater than or equal to the diameter of the communication openings 43.

[0118] In the above embodiments, the fluid control devices 111, 211, and 311 each include the blower section 13. However, the fluid control devices 111, 211, and 311 are not limited thereto, and may instead include another blower section.

[0119] For example, as in Fig. As illustrated in Figure 20, a fluid control device 411 may include the valve portion 12, the controller 14, and a blower portion 413. The blower portion 413 includes a vibration adjustment plate 454, a sidewall plate 431, a vibrating body 450, and a piezoelectric element 433.

[0120] The vibration adjustment plate 454 has a size different from that shown in the Fig. 3 and Fig. 8 in the surface direction. Other structures are the same as those of the vibration adjusting plate 54, and thus, a description thereof is omitted.

[0121] The side wall plate 431 has a size that differs from that shown in the Fig. 3 and Fig. 8 in the surface direction. Other structures are the same as those of the side wall plate 31, and thus, a description thereof is omitted.

[0122] The piezoelectric element 433 has a size different from that shown in the Fig. 3 and Fig. 8 in the surface direction. Other structures are the same as those of the piezoelectric element 33, and thus, a description thereof is omitted.

[0123] The vibrating body 450 includes a base plate 432, a reinforcement plate 436, and a restriction plate 460. The base plate 432 is disc-shaped and is made of, for example, stainless steel. The base plate 432 has intake openings 46.

[0124] The vibrating body 450 includes a peripheral region 451 and a central region 452. The peripheral region 451 extends from a node F, which is the outermost of the nodes of vibration pressure in the blower chamber 445 generated by bending vibration of the vibrating body 450, to the outer periphery of the blower chamber 445. The central region 452 is a region inside the peripheral region 451. The peripheral region 451 is a region in which the bending vibration of the peripheral region 451 is suppressed.

[0125] A restricting plate 460, which suppresses the bending vibration of the peripheral region 451, is added to the main surface of the bottom plate 432 facing the piezoelectric element 433. Accordingly, the thickness of the peripheral region 451 is greater than that of the central region 452. Therefore, the bending strength of the peripheral region 451 is higher than that of the central region 452. The restricting plate 460 is annular and is made of, for example, stainless steel.

[0126] The reinforcement plate 436 is disc-shaped and made of, for example, stainless steel. The reinforcement plate 436 is attached to the main surface of the bottom plate 432 facing away from the blower chamber 445. The reinforcement plate 436 prevents the piezoelectric element 433 from being damaged by bending.

[0127] Similar to the Fig. 9(A) and Fig.9(B), when the fluid control device 111 having the above-described structure is in operation, air is sucked through the suction ports 46 and discharged through the communication ports 43 into the valve chamber 40 in response to the flexural vibration of the vibrating body 450.

[0128] Although air is used as the fluid in the embodiments described above, the fluid is not limited thereto. The fluid may instead be a gas other than air.

[0129] In the embodiments described above, the plates included in the valve section and the fan section are made of SUS. However, the plates are not limited to this and may instead be made of other materials, such as aluminum, titanium, magnesium, or copper.

[0130] Furthermore, although the piezoelectric element is used as the driving source for the fan in the embodiments described above, the driving source is not limited thereto. For example, the fan may be electromagnetically driven to perform the pumping operation.

[0131] Furthermore, in the embodiments described above, the piezoelectric element is made of a lead titanate zirconate ceramic. However, the piezoelectric element is not limited to this and may instead be made of a lead-free piezoelectric ceramic material, such as a potassium sodium niobate ceramic or an alkali niobate ceramic. List of reference symbols 12 valve section 13 Blower section 14 controllers 21 Top plate 22 Side wall panel 23 Base plate 24 shift 25 lead 26 cut-out part 31 Side wall panel 32 base plate 33 piezoelectric element 34 Outer peripheral section 35 Beam part 36 Membran 37 piezoelectric actuator 40 valve chamber 41 Ejection opening 42 Layer opening 43 Communication opening 45 Blower chamber 46 Intake opening 48 lower blower chamber 49 Auxiliary opening 54 Vibration adjustment plate 55 upper blower chamber 111, 211 Fluid control device 212 valve section 221 top plate 248 Crosspiece part 249 Auxiliary opening 311 Fluid control device 312 valve section 321 top plate 349 Auxiliary opening 411 Fluid control device 413 Blower section 431 side wall panel 432 base plate 433 piezoelectric element 436 Reinforcement plate 445 Blower chamber 450 vibrating bodies 451 circumference 452 midrange 454 Vibration adjustment plate 460 Restriction plate

Claims

[1] Valve, comprising: a first plate (23) with a first ventilation opening (43); a second plate (21) defining a valve chamber (40) connected to the first opening (43) between the first plate (23) and the second plate (21), the second plate (21) having a second vent opening (41) connected to the valve chamber (40) and not facing the first vent opening (43); and a layer (24) arranged between the first plate (23) and the second plate (21), the layer (24) having a third ventilation opening (42) which is not opposite to the first opening (43) and which is opposite to the second ventilation opening (41), wherein the second plate (21) has an auxiliary opening (49) which overlaps the first vent opening (43) in a front view of a main surface of the second plate (21), the main surface facing the valve chamber (40), wherein on the first plate (23) there is provided a vibration adjusting plate (54, 454) in which an upper blower chamber (55) is formed, said upper blower chamber (55) being arranged to overlap all of the first vent openings (43) in the first plate (23), all of the second vent openings (41) in the second plate (21), and all of the third vent openings (42) in the layer (24). [2] Valve according to claim 1, wherein a center axis of the auxiliary opening (49) coincides with a center axis of the first vent opening (43). [3] A valve according to claim 1 or 2, wherein a plurality of said auxiliary openings (49) are provided, and wherein said second plate (21) includes a crosspiece portion provided between said auxiliary openings (49). [4] Valve according to one of claims 1 to 3, wherein a diameter of the auxiliary opening (49) is larger than a diameter of the first ventilation opening (43). [5] Valve according to one of claims 1 to 3, wherein a diameter of the auxiliary opening (49) is smaller than a diameter of the first ventilation opening (43). [6] A valve according to claim 4, wherein a plurality of the second vent holes (41) are provided on both sides of the auxiliary hole (49), and wherein, when rh is a radius of the first vent hole (43), Rs is a radius of the auxiliary hole (49), r1 and r2 are radii of two of the second vent holes (41) located on both sides of the auxiliary hole (49), and a is a distance between centers of the two of the second vent holes (41) located on both sides of the auxiliary hole (49), the following expression is satisfied: {a−(r1+r2)} / 2>Rs≥rh. [7] Fluid control device, comprising: the valve according to one of claims 1 to 6; and a blower (13; 413) including a blower chamber (55) connected to the first ventilation opening (43), a vibrating body (450) facing the blower chamber (55), and a drive body (433) generating bending vibration of the vibrating body (450). [8] Fluid control device according to claim 7, wherein the vibrating body (450) includes a peripheral region and a central region, the peripheral region extending from an outermost node of pressure vibration generated in the blower chamber (55) by the bending vibration of the vibrating body (450) to an outer periphery of the blower chamber (55), the central region being located within the peripheral region, and wherein the circumferential region is a region in which the bending vibration of the circumferential region is suppressed.

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