EP2306019A1 - Microsoufflante piézoélectrique - Google Patents

Microsoufflante piézoélectrique Download PDF

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Publication number
EP2306019A1
EP2306019A1 EP09754572A EP09754572A EP2306019A1 EP 2306019 A1 EP2306019 A1 EP 2306019A1 EP 09754572 A EP09754572 A EP 09754572A EP 09754572 A EP09754572 A EP 09754572A EP 2306019 A1 EP2306019 A1 EP 2306019A1
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EP
European Patent Office
Prior art keywords
blower
wall
driver
opening
center space
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Application number
EP09754572A
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German (de)
English (en)
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EP2306019A4 (fr
Inventor
Atsuhiko Hirata
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Murata Manufacturing Co Ltd
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Murata Manufacturing Co Ltd
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Publication date
Application filed by Murata Manufacturing Co Ltd filed Critical Murata Manufacturing Co Ltd
Publication of EP2306019A1 publication Critical patent/EP2306019A1/fr
Publication of EP2306019A4 publication Critical patent/EP2306019A4/fr
Withdrawn legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B43/00—Machines, pumps, or pumping installations having flexible working members
    • F04B43/02—Machines, pumps, or pumping installations having flexible working members having plate-like flexible members, e.g. diaphragms
    • F04B43/04—Pumps having electric drive
    • F04B43/043—Micropumps

Definitions

  • the present invention relates to a piezoelectric micro blower that is suited for transporting a compressible fluid such as air.
  • a piezoelectric micro pump is used for, for example, a pump for transporting water for cooling a small-sized electronic device such as a notebook computer and a pump for transporting fuel in a fuel cell.
  • a piezoelectric micro blower can be used as a blower that takes the place of a fan for cooling a CPU or the like or as a blower for supplying oxygen that is required for electric power generation in a fuel cell.
  • a piezoelectric micro pump / piezoelectric micro blower is a device that includes a diaphragm that becomes deformed due to flexion when a voltage is applied to a piezoelectric element.
  • the piezoelectric micro pump / piezoelectric micro blower has advantages of a simple structure, a low-profile body, and low power consumption.
  • check valves each of which is made of a soft material such as rubber or resin at an inlet port and an outlet port.
  • a piezoelectric element at a low frequency such as tens of hertz or so.
  • a check valve fails to operate in response thereto because the resonance frequency has a high frequency in kHz order. Therefore, it is preferable to use a piezoelectric micro blower that does not include any check valve for transporting a compressible fluid.
  • a flow generation device is disclosed in a patent Document 1.
  • the flow generation device disclosed therein includes a substrate that has a pressurizing chamber that is filled with a fluid, a nozzle plate that has nozzles that look out on the pressurizing chamber, an opening, and an electric vibrator that is attached to the nozzle plate in such a manner that the nozzles are located approximately at the center of the opening.
  • the nozzle plate and the electric vibrator are attached to the substrate.
  • An alternating current signal that has a frequency that is close to the resonance frequency of the electric vibrator is supplied to the electric vibrator.
  • a check valve can be omitted.
  • an air chamber into which air flows is provided in front of the nozzle plate.
  • a fluid that is ejected through the nozzles entrains ambient air in the air chamber.
  • the fluid is discharged through an exit port together with the entrained ambient air.
  • the open area of the air chamber is large, the pressure energy of the fluid that is ejected through the nozzles is dissipated into the periphery of the air chamber. For this reason, the structure disclosed therein has a disadvantage in that it is difficult to increase the rate of flow through the exit port.
  • a micro blower that includes an ejection unit that sucks air from the outside and ejects the air, a cover that has an exit port for discharging the air ejected from the ejection unit, and a base unit that is connected to the ejection unit is disclosed in a patent Document 2.
  • the following structure is disclosed in Fig. 4 of the patent Document 2.
  • the structure includes an ejection plate that has a suction hole and an ejection hole.
  • a vibration plate that is provided with a magnetic sheet is attached to the back of the ejection plate.
  • a pressurizing chamber is formed between the ejection plate and the vibration plate.
  • a coil is used to vibrate the magnetic sheet. Ejection airflow is generated from a cavity as a result of the vibration of the magnetic sheet.
  • the airflow entrains air in a cover cavity that is located in front of the ejection plate.
  • the fluid ejected is discharged through the exit port together with the entrained air. Since the open area of the cover cavity is larger than that of the pressurizing chamber, the pressure energy of the fluid that is ejected through the ejection hole is dissipated into the cover cavity. For this reason, the structure disclosed therein has the same disadvantage as that of the structure disclosed in the patent Document 1, that is, it is difficult to increase the rate of flow through the exit port.
  • An object of the invention is to provide a piezoelectric micro blower that makes it possible to transport a compressible fluid efficiently without using a check valve and to achieve an increase in the rate of flow.
  • the present invention provides a piezoelectric micro blower including a blower body, a driver that has a peripheral part that is fixed to the blower body and further has a piezoelectric element, and a blower chamber that is formed between the blower body and the driver, a voltage being applied to the piezoelectric element to cause the driver to vibrate due to flexion for transporting a compressible fluid.
  • the piezoelectric micro blower includes: a first wall of the blower body, the blower chamber being formed between the driver and the first wall; a first opening that is formed through the first wall, the inside of the blower chamber being in communication with the outside of the blower chamber through the first opening; a second wall that is provided at a side opposite the blower chamber with the first wall being provided between the second wall and the blower chamber, the second wall being provided at a distance from the first wall; a second opening that is formed through the second wall; a center space that is formed between the first wall and the second wall, has an open area that is larger than the first opening and the second opening but smaller than the blower chamber, and is in communication with the first opening and the second opening; and an inlet passage that has an outer end that is in communication with the outside of the piezoelectric micro blower and an inner end that is connected to the center space, wherein a bottleneck portion that has a passage area that is smaller than that of the inlet passage is formed in the inlet passage.
  • the inlet passage is connected to the center space between the first opening and the second opening. Since the inlet passage is not directly connected to the blower chamber, the inlet passage is less susceptible to a pressure change in the blower chamber. Even though a check valve is not provided, a fluid that flows at high speed from the first opening to the second opening does not flow backward into the inlet passage. Thus, it is possible to increase the rate of flow effectively.
  • the open area of the center space is larger than the first opening and the second opening but smaller than the blower chamber. The fluid entering from the inlet passage accumulates in the center space temporarily. Entrained by the flow of a fluid that is blown out through the first opening, the fluid that has accumulated in the center space is discharged through the second opening together with the fluid blown out through the first opening.
  • a fluid is sucked from the inlet passage into the center space by utilizing the pressure energy of a fluid pressed out of the blower chamber.
  • the fluid sucked from the inlet passage and the fluid pressed out of the blower chamber flow into each other to be discharged through the second opening. If the inlet passage were directly connected to the center space, the pressure energy of the fluid in the center space would be dissipated into the inlet passage.
  • a bottleneck portion that has a passage area that is smaller than that of the inlet passage is formed in the inlet passage.
  • the bottleneck portion is formed in the inlet passage, it is harder for pressure energy that is present inside the center space to be dissipated into the inlet passage. By this means, it is possible to direct the pressure energy toward the second opening efficiently, thereby achieving an increase in the rate of flow of a fluid discharged through the second opening.
  • the first opening should be formed at a part of the first wall that faces an area of the center of the driver.
  • the first opening since the first opening is formed at a position where it faces an area of the center of the driver, which is the area where the displacement of the driver is the largest, it is possible to obtain the maximum rate of flow.
  • the second opening should be formed at a part of the second wall that faces the first opening. With such a preferred structure, it is possible for a fluid ejected at high speed from the first opening to pass through the center space and be discharged through the second opening with lower resistance.
  • the bottleneck portion should be formed at a region of connection of the inlet passage and the center space.
  • the bottleneck portion may be formed anywhere in the inlet passage.
  • it is preferable to form the bottleneck portion at a position close to the center space because, with such a structure, it is harder for pressure energy that is present inside the center space to be dissipated into the inlet passage. By this means, it is possible to direct the pressure energy toward the second opening efficiently,
  • the passage area of the bottleneck portion should gradually decrease in a direction of a flow from the inlet passage to the center space. Since average pressure in the center space is lower than that in the inlet passage, there is a pressure gradient therebetween. Though there occurs pressure loss in a flow channel because of friction between a fluid and wall surfaces, if no bottleneck portion was formed therein, vena contracta would be produced in the vicinity of entrances to the center space because the pressure of the center space is lower than the pressure decreased due to the pressure loss. A vortex would form in the vicinity of the vena contracta, resulting in loss. For this reason, the rate of flow would decrease. To reduce such flow loss, the bottleneck portion is provided in the inlet passage.
  • the passage area of the bottleneck portion gradually decreases in a direction of a flow from the inlet passage to the center space.
  • the inlet passage should include a plurality of passages extending in radial directions from the center space.
  • the outer ends of the plural passages of the inlet passage should be respectively in communication with inlet ports.
  • the open area of the center space should be designed in such a manner that the part of the first wall that faces the center space vibrates as the driver vibrates.
  • the vibration of the first wall acts to increase the quantity of a fluid that is caused to flow by the driver. Since the quantity thereof increases because of the displacement of the first wall, it is possible to achieve a further increase in the rate of flow.
  • the part of the first wall that faces the center space should vibrate in a sympathetic manner as the driver vibrates. That is, it is possible to cause the first wall to vibrate in a sympathetic manner in response to or by following the displacement of the driver by making the natural vibration frequency of the part of the first wall that faces the center space close to the vibration frequency of the driver.
  • both the first wall and the driver may vibrate in the first-order mode or a higher-order mode (e.g., third-order mode).
  • a higher-order mode e.g., third-order mode
  • One of the first wall and the driver only may vibrate in the first-order mode.
  • the other may vibrate in a higher-order mode.
  • the driver according to the present invention may be, for example, a unimorph-type driver that has a structure in which a piezoelectric element that stretches and shrinks in a planar direction is attached to one surface of a diaphragm (a resin plate or a metal plate), a bimorph-type driver that has a structure in which piezoelectric elements that stretch and shrink in opposite directions are attached respectively to both surfaces of a diaphragm, or a bimorph-type driver that has a structure in which a multilayer piezoelectric element that becomes deformed due to flexion by itself is attached to one surface of a diaphragm.
  • the entire body of the driver may be configured as a multilayer piezoelectric element.
  • the shape of the piezoelectric element may be a disc, a rectangle, or a ring.
  • An intermediate plate may be sandwiched between the piezoelectric element and the diaphragm.
  • the structure may be modified in various ways as long as the driver vibrates in the direction of its thickness due to flexion when an alternating voltage (which is either a sinusoidal-wave voltage or a rectangular-wave voltage) is applied to the piezoelectric element.
  • the driver including the piezoelectric element in a first-order resonance mode (at a first-order resonance frequency) because the largest amount of displacement can be obtained in the first-order resonance mode.
  • the first-order resonance frequency is within an audible range, the problem of noise might arise.
  • a third-order resonance mode (a third-order resonance frequency) is used, it is possible to obtain the amount of displacement that is larger than that obtained when a resonance mode is not used at all, although the amount of displacement is smaller than that obtained in the first-order resonance mode.
  • first-order resonance mode means a mode in which the center part of the driver and the peripheral part thereof are displaced in the same direction.
  • third-order resonance mode means a mode in which the center part of the driver and the peripheral part thereof are displaced in opposite directions.
  • a piezoelectric micro blower can produce the following advantageous effects.
  • a driver is caused to vibrate due to bending so as to suck a fluid from a center space into a blower chamber through a first opening.
  • the fluid is pressed out of the blower chamber at high speed to be discharged through a second opening.
  • the fluid pressed out thereof entrains a fluid that is present inside the center space to be discharged together. Therefore, it is possible to obtain a discharging flow, the quantity of which is larger than the displacement volume of the driver, without any need to provide a check valve.
  • it is possible to provide a blower that is capable of blowing a large quantity of a fluid.
  • the bottleneck portion makes it harder for the energy of a pressure fluctuation in the center space to be dissipated into the inlet passage. Therefore, it is possible to direct the pressure energy toward the second opening efficiently. Consequently, it is possible to achieve a further increase in the rate of flow.
  • a piezoelectric micro blower according to a first embodiment of the present invention is shown in Figs. 1 to 4 .
  • a piezoelectric micro blower A according to the present embodiment of the invention is an air blower that is used for cooling electronic equipment.
  • the piezoelectric micro blower A includes a top plate (second wall) 10, a flow channel formation plate 20, a separator (first wall) 30, a blower frame member 40, a driver 50, and a bottom plate 60, which are fixed to form a layered structure in this order as viewed from the top.
  • the peripheral part of the driver 50 is fixed by bonding between the blower frame member 40 and the bottom plate 60.
  • the members mentioned above except the driver 50, that is, 10, 20, 30, 40, and 60, are components that make up a blower body 1. Each of them is made of a flat material having rigidity such as a metal plate or a hard resin plate.
  • the top plate 10 is a quadrangular flat plate.
  • a discharging port (second opening) 11 is formed as a through hole at the center of the top plate 10.
  • the flow channel formation plate 20 is also a flat plate that has the same outer shape as that of the top plate 10. As illustrated in Fig. 4 , a center hole (center space) 21 that has a diameter larger than that of the discharging port 11 is formed at the center of the flow channel formation plate 20. A plurality of inlet passages (in the illustrated example, four inlet passages) 22 extending in radial directions toward four corners is formed in the flow channel formation plate 20. The outer ends of the inlet passages 22 are respectively in communication with inlet ports 8, which will be explained later. In the present embodiment of the invention, the inlet passages 22 are in communication with the center hole 21 from four directions.
  • Each of the inlet passages 22 has a bottleneck portion 23.
  • the bottleneck portion 23 is the tapered part of the inlet passage 22 at which the width thereof becomes smaller toward the center hole 21.
  • the bottleneck portions 23 are formed at regions where the inlet passages 22 are connected to the center hole 21.
  • the regions where the bottleneck portions 23 are formed are not limited thereto.
  • the bottleneck portions 23 may be formed anywhere in the inlet passages 22.
  • the separator 30 is also a flat plate that has the same outer shape as that of the top plate 10.
  • a communication hole (first opening) 31 is formed at the center of the separator 30, specifically, at a position corresponding to the position of the discharging port 11.
  • the communication hole 31 has a diameter that is substantially the same as that of the discharging port 11.
  • the diameter of the communication hole 31 may be exactly the same as that of the discharging port 11.
  • the diameter of the communication hole 31 may be different from that of the discharging port 11. It is required that, however, said diameter is smaller than that of the center hole 21.
  • Inlet holes 32 are formed near four corners of the separator 30, specifically, at positions corresponding to the outer ends of the inlet passages 22, respectively.
  • the center of the discharging port 11, the center of the center hole 21, and the center of the communication hole 31 are aligned on the same axis.
  • the center of the aligned openings 11, 21, and 31 corresponds to the center of the driver 50, which will be explained later.
  • the separator 30 should be made of a thin metal plate so that a part of the separator 30 that is located at an area corresponding to the center hole 21 can be vibrated in a sympathetic manner.
  • the blower frame member 40 is also a flat plate that has the same outer shape as that of the top plate 10.
  • a circular cavity 41 having a large diameter is formed at the center of the blower frame member 40.
  • Inlet holes 42 are formed near four corners of the blower frame member 40, specifically, at positions corresponding to the positions of the inlet holes 32, respectively. Since the blower frame member 40 is fixed by bonding between the separator 30 and the driver 50, the cavity 41 of the blower frame member 40 is formed as a blower chamber.
  • the blower chamber 41 is not limited to an enclosed space.
  • the blower chamber 41 may be a partially open space.
  • the bottom plate 60 is also a flat plate that has the same outer shape as that of the top plate 10.
  • a cavity 61 is formed at the center of the bottom plate 60.
  • the two-dimensional shape of the cavity 61 is substantially the same as that of the blower chamber 41.
  • the bottom plate 60 has a thickness that is greater than the sum of the thickness of a piezoelectric element 52 and the amount of displacement of a diaphragm 51. With such a structure, when the piezoelectric micro blower A is mounted on, for example, a substrate, it is possible to avoid the contact of the piezoelectric element 52 with the substrate.
  • the wall of the cavity 61 surrounds the piezoelectric element 52 of the driver 50, which will be explained later.
  • Inlet holes 62 are formed near four corners of the bottom plate 60, specifically, at positions corresponding to the positions of the inlet holes 32 and 42, respectively.
  • the driver 50 includes the diaphragm 51 and the piezoelectric element 52.
  • the piezoelectric element 52 which has a circular shape is attached to the lower surface of the diaphragm 51 at the center area thereof.
  • resin can be used as the material of the diaphragm 51.
  • a resin plate that is made of glass epoxy resin may be used as the diaphragm 51.
  • the piezoelectric element 52 has the shape of a disc having a diameter smaller than that of the cavity 41 of the blower frame member 40.
  • single-plate piezoelectric ceramics having electrodes on both surfaces is used as the piezoelectric element 52.
  • the piezoelectric element 52 is attached to the back of the diaphragm 51 (i.e., one surface of the diaphragm 51 that is opposite to the other surface facing the blower chamber 41). That is, the driver 50 is configured as a unimorph driver. When an alternating voltage (either a sinusoidal wave or a rectangular wave) is applied to the piezoelectric element 52, the piezoelectric element 52 extends and contracts in a planar direction. As a result, the displacement of the entire body of the driver 50 in the direction of its thickness occurs due to bending.
  • an alternating voltage either a sinusoidal wave or a rectangular wave
  • the alternating voltage applied to the piezoelectric element 52 causes the driver 50 to become displaced either in a first-order resonance mode or in a third-order resonance mode due to bending, Since such a voltage is applied thereto, it is possible to significantly increase the displacement volume of the driver 50 as compared with a case where a voltage having any frequency other than the above is applied thereto. Consequently, it is possible to significantly increase the rate of flow.
  • Inlet holes 51 a are formed near four corners of the diaphragm 51, specifically, at positions corresponding to the positions of the inlet holes 32, 42, and 62, respectively.
  • the inlet holes 32, 42, 51 a, and 62 are aligned in such a manner that they make up each of the inlet ports 8.
  • One end of the inlet port 8 is formed as a downward open end. The other end of the inlet port 8 is in communication with the inlet passage 22.
  • the inlet ports 8 of the piezoelectric micro blower A are open at the bottom of the blower body 1.
  • the discharging port 11 is open at the top of the blower body 1.
  • a compressible fluid can be sucked into the inlet ports 8 through the open ends thereof, which are formed at the reverse side of the piezoelectric micro blower A, and then can be discharged from the discharging port 11, which is formed at the front side of the piezoelectric micro blower A.
  • Such a structure is suited for use as a blower for supplying air to a fuel cell or a blower for cooling a CPU by means of air. It is not always necessary that the open ends of the inlet ports 8 be oriented downward. They may be open at the sides.
  • the driver 50 illustrated in Fig. 3 is made up of the diaphragm 51 and the piezoelectric element 52
  • the structure of the driver 50 is not limited to the illustrated example.
  • the driver 50 may further include an intermediate plate 53 that is sandwiched between the diaphragm 51 and the piezoelectric element 52.
  • a plate that is made of metal such as SUS can be used as the intermediate plate 53. Since the intermediate plate 53 is sandwiched between the diaphragm 51 and the piezoelectric element 52, a neutral plane at the time of the displacement of the driver 50 due to bending is located inside the intermediate plate 53, which results in greater displacement efficiency. Therefore, it is possible to provide a piezoelectric micro blower that can offer a high flow rate with a low voltage.
  • Fig. 5 is a diagram that schematically illustrates an example of the operation of the piezoelectric micro blower A. To facilitate understanding, displacement is shown in an exaggerated manner. An initial state (when no voltage is applied thereto) is shown in Fig. 5(a). Figs. 5(b) to 5(e) illustrate the displacement of the driver 50 and the separator 30 at intervals of 1/4 in a cycle of a voltage (e.g., sinusoidal wave) applied to the piezoelectric element 52. As a result of the application of an alternating voltage to the piezoelectric element 52, operations shown in Figs. 5(b) to 5(e) are repeated in a cycle. As illustrated therein, the vibration of the driver 50 causes the sympathetic vibration of the separator 30.
  • a voltage e.g., sinusoidal wave
  • the vibration of the separator 30 occurs with a delay of a predetermined phase (in this example, approximately 90°) with respect to the vibration of the driver 50. Because of the sympathetic vibration of the separator 30, a large pressure wave is generated from the first opening 31 in an upward direction. Air is forced out of the center space 21 through the second opening 11 to the outside due to the pressure wave. Therefore, it is possible to increase the rate of flow as compared with a case where the separator 30 is not vibrated in a sympathetic manner. Since the air is forced out of the center space 21, new air is sucked from the inlet passages 22 into the center space 21, thereby generating a continuous airflow exiting from the second opening 11.
  • a predetermined phase in this example, approximately 90°
  • Fig. 5 an example of the displacement of the driver 50 in a first-order resonance mode is illustrated.
  • the same principle holds true for displacement in a third-order resonance mode.
  • the amount of displacement of the separator 30 is larger than that of the driver 50.
  • the Young's modulus of the separator 30, the thickness of the separator 30, and the like there is a possibility that the amount of displacement of the separator 30 is smaller than that of the driver 50.
  • the phase delay of the separator 30 with respect to the driver 50 is not limited to 90°.
  • the above structure may be modified as long as the vibration of the separator 30 occurs with a certain delay with respect to the vibration of the driver 50, and, for this reason, an actual change in the distance between the driver 50 and the separator 30 is greater than a change that would occur if the separator 30 did not vibrate at all.
  • a unimorph element that includes a diaphragm, a single-plate piezoelectric ceramic element, and an intermediate plate that is sandwiched between the diaphragm and the piezoelectric ceramic element was used as the driver.
  • the diaphragm is made of a 42Ni plate having a thickness of 0.08 mm.
  • the intermediate plate is an SUS430 plate having a thickness of 0.15 mm and a diameter of 11 mm.
  • the piezoelectric ceramic element has a thickness of 0.2 mm and a diameter of 11 mm.
  • Blower chamber 0.15 mm in height, 16 mm in diameter Blower body: 20 mm in length, 20 mm in width, 2.4 mm in height Separator: SUS430 having a thickness of 0.05 mm First opening: 0.6 mm in diameter Second opening: 0.8 mm in diameter Center space: 6 mm in diameter, 0.5 mm in height Inlet passages: 2.5 mm in width, 0.5 mm in height, four passages Bottleneck portions: 1 mm in width
  • a voltage having a sinusoidal waveform of 24 kHz and 20 Vp-p was applied to the piezoelectric micro blower A having the above specifications.
  • the rate of flow was 0.9 Umin under 100 Pa condition.
  • the driver was energized in the third-order mode.
  • the driver may be energized in the first-order mode.
  • Another experiment was conducted for comparison with the use of a piezoelectric micro blower having the same specifications as above except that it does not have any bottleneck portion.
  • the rate of flow was 0.77 L/min under 100 Pa condition. From the above results, it was found that the bottleneck portions contribute to an increase in the rate of flow.
  • inlet passages 22 have the bottleneck portions 23, it is harder for pressure energy that is present inside the center space 21 to be dissipated into the inlet passages 22. By this means, it is possible to direct the pressure energy that is present inside the center space 21 toward the second opening 11 efficiently, thereby achieving an increase in the rate of flow.
  • the bottleneck portions 23 are formed in the vicinity of entrances to the center space 21, the conformity of the shape of the flow channel to the shape of the flow increases. With the increased conformity, it is possible to suppress the forming of a vortex and thus reduce flow loss. Consequently, the rate of flow of the blower increases.
  • the separator 30 is attached to the flow channel formation plate 20.
  • the center area of the separator 30 that corresponds to the center space 21 is configured as a regional part that can vibrate. As illustrated in Fig. 5 , the vibration of the center area of the separator 30 has a strong bearing on the rate of flow.
  • the size of the center space 21 (open area) is designed to have an appropriate diameter that makes it easier for the center area of the separator 30 to vibrate. However, it is impossible to restrain the separator 30 at regions where the inlet passages 22 are connected to the center space 21.
  • the flow channel formation plate 20 having the bottleneck portions 23 since the front end of each of the bottleneck portions 23 has a tapered structure, the area where the sidewalls of the center space 21 exist is relatively large. That is, as compared with a case where there is not any bottleneck portion, it is possible to increase the area where the separator 30 is supported.
  • the shape of the area where the separator 30 is supported is close to a circle. Having the bottleneck portions 23, the flow channel formation plate 20 can support the center area of separator 30 more securely, which contributes to an increase in the rate of flow.
  • Table 1 shows the rate of flow obtained when the drive frequency of the driver 50 and the diameter of the center space 21 are changed.
  • the unit of the rate of flow is L/min.
  • a diaphragm (42Ni plate) having a thickness of 0.08 mm was used for a drive frequency of 24.4 kHz.
  • a diaphragm (42Ni plate) having a thickness of 0.1 mm was used for a drive frequency of 25.5 kHz.
  • the rate of flow increases as the frequency increases when the diameter of the center space 21 is 5 mm, whereas the rate of flow increases as the frequency decreases when the diameter of the center space 21 is 6 mm.
  • the reason can be inferred as follows.
  • the natural vibration frequency of the driver 50 differs depending on the material of the diaphragm 51 and the thickness thereof. It is possible to make the natural vibration frequency of the center area of the separator 30 that corresponds to the center space 21 close to the natural vibration frequency of the driver 50 by adjusting the diameter of the center space 21, thereby causing the sympathetic vibration of the separator 30. By this means, the rate of flow increases.
  • Fig. 7 shows the result of an experiment conducted on a piezoelectric micro blower B having a structure in which the driver 50 includes the diaphragm 51, the piezoelectric element 52, and the intermediate plate 53 that is sandwiched between the diaphragm 51 and the piezoelectric element 52.
  • Table 2 the experiment was conducted to compare the rate of flow obtained when the material of the separator 30 and the thickness thereof are changed.
  • a plate that is made of phosphor bronze and has a thickness of 0.05 mm was used as a separator in a first sample.
  • a plate that is made of SUS304 and has a thickness of 0,1 mm was used as a separator in a second sample.
  • the specifications of the piezoelectric micro blower B are the same as those of the piezoelectric micro blower A.
  • the specifications of the first sample are the same as those of the second sample except for the separator.
  • the drive frequency of 24.4 kHz was used for both the first sample and the second sample.
  • a plate that is made of SUS304 and has a certain thickness is one and a half times as rigid as a plate that is made of phosphor bronze and has the same thickness. Since the separator of the second sample is twice as thick as the separator of the first sample, the rigidity of the separator of the second sample is far greater than the rigidity of the separator of the first sample. In other words, presumably, a regional part of the separator of the first sample that faces the center space can vibrate, whereas a regional part of the separator of the second sample that faces the center space can hardly vibrate.
  • the purpose of the experiment is to measure the influence of the vibration of a regional part of the separator that faces the center space on the rate of flow.
  • the rate of flow of the second sample obtained when a voltage of 20 Vp-p was applied thereto was approximately 0.42 L/min.
  • the rate of flow of the first sample obtained when the same voltage of 20 Vp-p was applied thereto was approximately 0.78 L/min. Therefore, the rate of flow of the first sample is roughly twice as high as the rate of flow of the second sample. That is, it can be understood that the vibration of the above part of the separator contributes much to an increase in the rate of flow.
  • Fig. 7(b) shows the result of comparison of the rate of flow based on power consumption. Though power consumption changes due to a change in impedance, it can be understood that the first sample is advantageous when compared on the basis of the same power consumption.
  • Fig. 8 illustrates the shape of bottleneck portions according to another embodiment of the invention. Since the structure of the flow channel formation plate 20 according to the present embodiment of the invention is the same as that of the first embodiment of the invention (refer to Fig. 4 ) except for the shape of bottleneck portions, the same reference numerals are used for the components described earlier. The components described earlier are not explained below.
  • bottleneck portions 24 that are not tapered are formed at regions where the inlet passages 22 are connected to the center space 21. As in the foregoing structure, the bottleneck portions 24 make it harder for the energy of a pressure fluctuation in the center space 21 to be dissipated into the inlet passages 22. By this means, it is possible to achieve an increase in the rate of flow.
  • a part of a separator (first wall) that corresponds to a center space vibrates in a sympathetic manner as a driver vibrates.
  • the separator it is not always necessary for the separator to vibrate in a sympathetic manner.
  • Any alternative structure in which the vibration of a driver excites a separator, and, in addition, the separator vibrates in response to or by following the vibration of the driver makes it possible to achieve an increase in the rate of flow.
  • the shape of an inlet passage is not limited to a linear passage extending in a radial direction as shown in Fig. 4 . That is, the shape of the inlet passage may be selected arbitrarily.
  • the number of inlet passages may also be selected arbitrarily depending on the rate of flow and the level of noise.
  • a plurality of plate members is fixed in layers to form a blower body.
  • the structure of the blower body is not limited thereto.
  • the top plate 10 and the flow channel formation plate 20 may be molded integrally as a single component that is made of resin or metal. The same applies for, for example, the separator 30 and the blower frame member 40, or the flow channel formation plate 20 and the separator 30.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)
EP09754572.7A 2008-05-30 2009-05-14 Microsoufflante piézoélectrique Withdrawn EP2306019A4 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008142250 2008-05-30
PCT/JP2009/058968 WO2009145064A1 (fr) 2008-05-30 2009-05-14 Microsoufflante piézoélectrique

Publications (2)

Publication Number Publication Date
EP2306019A1 true EP2306019A1 (fr) 2011-04-06
EP2306019A4 EP2306019A4 (fr) 2014-10-15

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Country Status (4)

Country Link
US (1) US20110070110A1 (fr)
EP (1) EP2306019A4 (fr)
JP (1) JP5287854B2 (fr)
WO (1) WO2009145064A1 (fr)

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CN103016317A (zh) * 2012-12-13 2013-04-03 江苏大学 一种基于附壁效应的三腔无阀压电泵
WO2015059426A1 (fr) 2013-10-24 2015-04-30 Universite Sciences Technologies Lille Procede pour generer un ecoulement de fluide
CN107795465A (zh) * 2016-09-05 2018-03-13 研能科技股份有限公司 微型流体控制装置
EP3364031A1 (fr) * 2017-02-20 2018-08-22 Microjet Technology Co., Ltd Dispositif de transport de gaz miniature
US10697448B2 (en) 2016-09-05 2020-06-30 Microjet Technology Co., Ltd. Miniature fluid control device
EP4006367A1 (fr) 2020-11-27 2022-06-01 European Space Agency Système de palier à gaz

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JP5528404B2 (ja) * 2011-09-06 2014-06-25 株式会社村田製作所 流体制御装置
JP5682513B2 (ja) * 2011-09-06 2015-03-11 株式会社村田製作所 流体制御装置
JP5533823B2 (ja) * 2011-09-06 2014-06-25 株式会社村田製作所 流体制御装置
CN103339380B (zh) 2011-10-11 2015-11-25 株式会社村田制作所 流体控制装置、流体控制装置的调节方法
WO2013125364A1 (fr) * 2012-02-21 2013-08-29 株式会社村田製作所 Dispositif de commande de fluide
JP5928160B2 (ja) * 2012-05-29 2016-06-01 オムロンヘルスケア株式会社 圧電ポンプおよびこれを備えた血圧情報測定装置
WO2014174957A1 (fr) 2013-04-24 2014-10-30 株式会社村田製作所 Dispositif de régulation de pression de manchette
KR20150085612A (ko) * 2014-01-16 2015-07-24 삼성전기주식회사 마이크로 펌프
GB2538413B (en) * 2014-03-07 2020-08-05 Murata Manufacturing Co Blower
JP6052475B2 (ja) 2014-07-16 2016-12-27 株式会社村田製作所 流体制御装置
WO2016140181A1 (fr) * 2015-03-03 2016-09-09 株式会社村田製作所 Dispositif d'aspiration
TWI557321B (zh) * 2015-06-25 2016-11-11 科際精密股份有限公司 壓電泵及其操作方法
US10451051B2 (en) 2016-01-29 2019-10-22 Microjet Technology Co., Ltd. Miniature pneumatic device
US10371136B2 (en) 2016-01-29 2019-08-06 Microjet Technology Co., Ltd. Miniature pneumatic device
EP3203076B1 (fr) 2016-01-29 2021-05-12 Microjet Technology Co., Ltd Dispositif miniature de régulation de fluides
US10388849B2 (en) 2016-01-29 2019-08-20 Microjet Technology Co., Ltd. Piezoelectric actuator
US10529911B2 (en) 2016-01-29 2020-01-07 Microjet Technology Co., Ltd. Piezoelectric actuator
EP3203081B1 (fr) 2016-01-29 2021-06-16 Microjet Technology Co., Ltd Dispositif de contrôle de fluides miniature
US10487820B2 (en) 2016-01-29 2019-11-26 Microjet Technology Co., Ltd. Miniature pneumatic device
US10388850B2 (en) 2016-01-29 2019-08-20 Microjet Technology Co., Ltd. Piezoelectric actuator
US10584695B2 (en) 2016-01-29 2020-03-10 Microjet Technology Co., Ltd. Miniature fluid control device
EP3203077B1 (fr) 2016-01-29 2021-06-16 Microjet Technology Co., Ltd Actionneur piézoélectrique
EP3203080B1 (fr) 2016-01-29 2021-09-22 Microjet Technology Co., Ltd Dispositif pneumatique miniature
US10746169B2 (en) 2016-11-10 2020-08-18 Microjet Technology Co., Ltd. Miniature pneumatic device
US10655620B2 (en) 2016-11-10 2020-05-19 Microjet Technology Co., Ltd. Miniature fluid control device
US10683861B2 (en) 2016-11-10 2020-06-16 Microjet Technology Co., Ltd. Miniature pneumatic device
TWI652652B (zh) * 2017-08-21 2019-03-01 研能科技股份有限公司 具致動傳感模組之裝置
TWI663332B (zh) * 2017-08-31 2019-06-21 研能科技股份有限公司 氣體輸送裝置
TWI698584B (zh) * 2017-08-31 2020-07-11 研能科技股份有限公司 氣體輸送裝置
TWI683059B (zh) * 2017-08-31 2020-01-21 研能科技股份有限公司 氣體輸送裝置
GB2583226B (en) * 2018-02-16 2022-11-16 Murata Manufacturing Co Fluid control apparatus
TWI695934B (zh) * 2019-03-29 2020-06-11 研能科技股份有限公司 微機電泵浦
CN114728281B (zh) * 2019-10-18 2023-11-03 瞬知（广州）健康科技有限公司 用于输注流体的系统和方法

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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103016317A (zh) * 2012-12-13 2013-04-03 江苏大学 一种基于附壁效应的三腔无阀压电泵
CN103016317B (zh) * 2012-12-13 2015-07-08 江苏大学 一种基于附壁效应的三腔无阀压电泵
WO2015059426A1 (fr) 2013-10-24 2015-04-30 Universite Sciences Technologies Lille Procede pour generer un ecoulement de fluide
FR3012443A1 (fr) * 2013-10-24 2015-05-01 Univ Sciences Technologies Lille Procede pour generer un ecoulement de fluide
US10519945B2 (en) 2013-10-24 2019-12-31 Université de Lille Method for generating a flow of fluid
CN107795465A (zh) * 2016-09-05 2018-03-13 研能科技股份有限公司 微型流体控制装置
US10697448B2 (en) 2016-09-05 2020-06-30 Microjet Technology Co., Ltd. Miniature fluid control device
EP3364031A1 (fr) * 2017-02-20 2018-08-22 Microjet Technology Co., Ltd Dispositif de transport de gaz miniature
EP4006367A1 (fr) 2020-11-27 2022-06-01 European Space Agency Système de palier à gaz
US12077322B2 (en) 2020-11-27 2024-09-03 European Space Agency Gas bearing system

Also Published As

Publication number Publication date
US20110070110A1 (en) 2011-03-24
JPWO2009145064A1 (ja) 2011-10-06
EP2306019A4 (fr) 2014-10-15
WO2009145064A1 (fr) 2009-12-03
JP5287854B2 (ja) 2013-09-11

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