JP2007222727A - Vibration actuator and jet generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration actuator which is capable of reducing the power consumption in a jet generator to generate gas combined jet. <P>SOLUTION: An elastic support member 36 is designed so that when the elastic support member 36 moves to the upper side spring force becomes smaller than spring force when the elastic support member 36 moves to the bottom side. The static position of the vibration plate 33 is set at the lower side from the center of electromagnetic force generated by a driving mechanism 35 consisting of a magnet 27, a bottom york 26, a top york 34 and a coil 28. In other word, the center position of electromagnetic force generated from the driving mechanism 35 is set so that it is shifted upward to the vibration direction from the static position of the vibration plate 33 (position of the center of gravity of the vibration plate 33). Thus, the vibration plate 33 tends to move around the center position of the driving force of a magnetic circuit when the vibration plate 33 is driven by the magnetic force. The center of vibration of the vibration plate 33 is lifted and then can be driven with a small electric current. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a jet generating device that generates a synthetic jet of gas and a vibration actuator mounted thereon.

  Conventionally, an increase in the amount of heat generated from a heating element such as an IC (Integrated Circuit) associated with high performance of a PC (Personal Computer) has been a problem, and various heat radiation technologies have been proposed or commercialized. Yes.

  As a heat dissipation method, a composite jet is generated by discharging air in a pulsating flow, and this combined jet is supplied to a heat dissipation fin (heat sink), etc., and the temperature boundary layer formed on the surface of the heat dissipation fin is efficient. There is a method of well destroying and dissipating heat (see, for example, Patent Document 1). Such a jet generating device has a housing having an opening and a diaphragm that causes a pressure change in the air in the housing. When the diaphragm vibrates, a pressure change occurs in the casing, and air is discharged as a pulsating flow through the opening, thereby generating a synthetic jet.

  The synthetic jet is generated according to the following principle. As air flows when air is discharged from the opening of the housing, the air pressure around the opening outside the housing is reduced, so that the surrounding air is caught in the air discharged from the opening. A synthetic jet is generated.

Moreover, since the jet flow generator described in Patent Document 1 alternately discharges air from the two chambers, that is, discharges air in opposite phases, sounds generated from the respective chambers and openings (nozzles) weaken each other. This reduces noise.
Japanese Patent Laying-Open No. 2005-256834 (paragraph [0079], FIG. 1)

  In order to commercialize a jet generator that generates such a synthetic jet, it is an important issue to reduce power consumption.

  In view of the circumstances as described above, it is an object of the present invention to provide a vibration actuator capable of reducing power consumption and a jet flow generation device equipped with the vibration actuator.

  In order to achieve the above object, a vibration actuator according to the present invention is a vibration actuator used in a jet generating device that generates a synthetic jet of gas, and supports the vibration body and the vibration body so as to vibrate. An elastic support member having a non-linear spring force with respect to the displacement and a center position of the driving force in the vibration direction of the vibrating body deviate by a predetermined distance in the vibration direction from a center of gravity position of the vibrating body in a stationary state, A driving mechanism for driving the vibrating body.

  In the present invention, when the spring force of the elastic support member is non-linear, the center position of the driving force is not the center of gravity position when the vibrating body is stationary, but is shifted from the center of gravity position by a predetermined distance in the vibration direction. By setting appropriately, low power consumption can be achieved.

  In the present invention, the elastic support member has a first spring force at a position displaced from the center of gravity position to the first side by a first distance, and is opposite to the first side from the center of gravity position. A second spring force that is smaller than the first spring force at a position displaced by the same distance as the first distance, and the drive mechanism drives the drive to the second side. The vibrating body is driven so that the center position of the force is shifted. Thereby, power consumption can be minimized.

  In the present invention, the elastic support member supports a periphery in a plane substantially perpendicular to the vibration direction of the vibrating body, and is a bellows-like member provided with one peak on the outer peripheral side and one trough on the inner peripheral side. It is.

  In the present invention, the drive mechanism is mounted on the magnet so as to form a magnetic gap between the magnet, a cylindrical first yoke that houses the magnet, and the first yoke. A plate-shaped second yoke having a thickness of 1.0 to 1.7 (mm) and a coil disposed in the magnetic gap and connected to the vibrating body, and a predetermined current is applied to the coil When this is done, the maximum value of the magnetic flux density at the center position in the thickness direction of the second yoke is configured to be 1.5 to 2.1 (T). According to such a drive mechanism configuration, magnetic flux is efficiently generated between the magnetic gaps, and power consumption is reduced. The “coil connected to the vibrating body” means that the coil does not have to be directly connected to the vibrating body, and the vibrating body and the coil need only move together.

  A vibration actuator according to another aspect of the present invention is a vibration actuator used in a jet generating device that generates a synthetic jet of gas, and includes a vibrating body, a magnet, and a cylindrical first yoke that houses the magnet. And a plate-shaped second yoke having a thickness of 1.0 to 1.7 (mm), which is mounted on the magnet so as to form a magnetic gap between the first yoke and the first yoke. A coil disposed in the gap and connected to the vibrating body, and when a predetermined current is applied to the coil, the maximum value of the magnetic flux density at the central position in the thickness direction of the second yoke is And a drive mechanism configured to be 1.5 to 2.1 (T).

  A jet flow generating apparatus according to the present invention includes a housing having an opening and containing gas therein, a vibrating body that is disposed in the housing and discharges the gas through the opening by vibration, and the vibrating body. An elastic support member that is supported so as to vibrate and has a non-linear spring force with respect to the displacement of the vibrating body, and the center position of the driving force in the vibration direction of the vibrating body is determined from the position of the center of gravity of the vibrating body in the vibration direction. And a drive mechanism for driving the vibrating body so as to be shifted by a predetermined distance.

  A jet flow generating device according to another aspect of the present invention includes a housing having an opening and containing a gas therein, a vibrating body disposed in the housing and discharging the gas through the opening by vibration, Thickness of 1.0 to 1.7 (mounted on the magnet so as to form a magnetic gap between the magnet, a cylindrical first yoke that accommodates the magnet, and the first yoke) mm) and a coil disposed in the magnetic gap and connected to the vibrating body, and when a predetermined current is applied to the coil, the second yoke And a drive mechanism configured such that the maximum value of the magnetic flux density at the center position in the thickness direction is 1.5 to 2.1 (T).

  As described above, according to the present invention, it is possible to reduce the power consumption of the vibration actuator mounted on the jet generating device that generates the combined gas jet.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing a jet flow generating apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the jet flow generating device shown in FIG.

  The jet flow generator 10 includes a housing 1, a nozzle body 2 attached to the housing 1, and a vibration actuator 15 disposed in the housing 1. The nozzle body 2 is mounted on the front surface 1a of the housing 1, and a plurality of air flow paths (openings) 2a are provided in the upper stage, and a plurality of air flow paths 2b are provided in the lower stage. Between the upper and lower flow paths 2a and 2b, as many partition plates 2c as the number of the flow paths 2a (or 2b) arranged in the X direction are provided. As will be described later, when the jet flow generator 10 operates, the wind direction is always reversed in the upper and lower flow paths 2a and 2b. By providing the partition plate 2c, for example, air discharged from the flow path 2b is not easily sucked from the flow path 2a, and air is efficiently discharged.

  Although a plurality of partition plates 2c are provided, the partition plate 2c is not limited to such a form, and may be configured by a single plate extending in the X direction. However, since the partition plate 2c is divided into a plurality of parts as shown in FIG. 1 and the like, the partition plates 2c can be fitted between the heat radiation fins constituting the heat sink (not shown). Thereby, the jet flow generator 10 and the heat sink can be positioned easily and accurately.

  As shown in FIG. 2, the housing 1 includes a vibration actuator 15 having a plate-like vibrating body (hereinafter referred to as a diaphragm) 33, a drive mechanism 35, and an elastic support member 36. The elastic support member 36 elastically supports the periphery of the diaphragm 33. A flat frame 328 is provided in the housing 1, and an elastic support member 36 is attached to the frame 328.

  FIG. 3 is an enlarged cross-sectional view of the diaphragm 33 and the elastic support member 36. As described above, the elastic support member 36 has a bellows shape in which one peak 36a and one valley 36b are provided. In this example, the peak 36a is provided on the outer peripheral side, and the valley 36b is provided on the inner peripheral side. However, the peak 36a may be provided on the inner peripheral side, and the valley 36b may be provided on the outer peripheral side.

  FIG. 4 is a perspective view showing the diaphragm 33, the elastic support member 36, and the frame 328 individually. The elastic support member 36 has a hole 36c, and the diaphragm 33 is connected to the inner peripheral portion 36d of the elastic support member so as to close the hole 36c. Further, the frame 328 has a hole 328a, and the elastic support member 36 is attached to the frame 328 at the outer peripheral portion 36e of the elastic support member 36 so as to close the hole 328a. Since the frame 328 is flat, assembly is easy, that is, manufacture is easy.

  The elastic support member 36 is made of rubber or resin. When the elastic support member 36 is an elastic support member composed of only one valley or only one mountain, the height in the vertical direction in FIG. 2 is increased and the thickness is increased. When there are a plurality of peaks and valleys, when the diaphragm 33 vibrates, there is a possibility that complicated movements other than the vibration direction (Z direction) may occur, and the efficiency may decrease. Moreover, there is a risk that noise will increase. Therefore, it is desirable to use the elastic support member 36 having one peak 36a and one valley 36b as shown in FIG. However, such an elastic support member 36 does not necessarily have to be used.

  The frame 328 and the elastic support member 36 may be manufactured by integral molding. That is, an elastic support member made of rubber, resin, or the like is molded in a state where the frame 328 prepared in advance is disposed in a mold for molding the elastic support member 36, for example. As an integral molding method, for example, a compression method, a transfer method, an injection method, or other known methods are used. The integral molding not only reduces the manufacturing process, but also significantly improves the positional accuracy of the elastic support member 36 and the frame 328, and consequently the positional accuracy of the elastic support member 36 and the housing 1.

  The elastic support member 36 and the diaphragm 33 may be integrally formed. In this case, as in the case of the frame 328, the elastic support member is molded in a state where the vibration plate 33 prepared in advance is arranged in a mold for molding the elastic support member 36.

  As shown in FIG. 2, the inside of the housing 1 is divided into two by the diaphragm 33 and the elastic support member 36, and the chambers 3 and 4 are formed. The chamber 3 formed in the upper part communicates with the outside of the housing 1 through the flow path 2a, and the chamber 4 formed in the lower part communicates with the outside of the housing 1 through the flow path 2b. Yes.

  The drive mechanism 35 is disposed, for example, in the lower chamber 4. For example, a magnet 27 magnetized in the vibration direction (Z direction) of the diaphragm 33 is incorporated inside the cylindrical bottom yoke 26, and a plate-like top yoke 34 is attached to the magnet 27, for example. The magnet 27, the bottom yoke 26, and the top yoke 34 constitute a magnetic circuit. For example, the shape of the bottom yoke 26 and the top yoke 34 in a plane substantially perpendicular to the vibration direction may be any shape such as a circle, an ellipse, or a polygon. The in-plane shape of the magnet 27 is, for example, a ring shape or a cylindrical shape if the bottom yoke 26 and the top yoke 34 are circular. A coil bobbin 29 around which a coil 28 is wound enters and exits a magnetic gap between the top yoke 34 and the bottom yoke 26. The coil bobbin 29 is attached to the lower surface of the diaphragm 33. By supplying an electrical signal from the drive signal generator 5 to the drive mechanism 35 configured as described above, the diaphragm 33 can be vibrated in the Z direction.

  The diaphragm 33 is made of, for example, resin, paper, or metal. In particular, when the diaphragm 33 is made of paper, the weight is very reduced. Paper is not as easy to make in an arbitrary shape as resin, but it is advantageous in reducing the weight. When the diaphragm 33 is a resin, it can be easily formed into an arbitrary shape by molding. On the other hand, when the diaphragm 33 is a metal, it is made of, for example, copper, aluminum, or stainless steel. Alternatively, magnesium may be used. Magnesium is advantageous because it is lightweight and can be injection molded. The diaphragm 33 may not be a flat plate, and may be, for example, a three-dimensional vibrator. The planar shape of the diaphragm 33 (the shape of the surface substantially perpendicular to the vibration direction) may be a circle, an ellipse, a rectangle, or a combination thereof.

  The housing 1 is made of, for example, resin, rubber, or metal. Resin and rubber are easy to produce by molding and are suitable for mass production. Further, when the housing 1 is made of resin or rubber, it is possible to suppress sound generated by driving the vibration actuator 15 or airflow sound generated by vibration of the vibration plate 33. That is, when the housing 1 is made of resin or rubber, the attenuation rate of those sounds is also high, noise can be suppressed, and further, the weight can be reduced and the cost is reduced. When the housing 1 is manufactured by injection molding of resin or the like, it can be molded integrally with the nozzle body 2. However, as shown in FIGS. 1 and 2, the jet flow generating device 10 can be easily manufactured when the casing 1 and the nozzle body 2 are separate.

  When the housing 1 is made of a material having high thermal conductivity, for example, metal, heat generated from the drive mechanism 35 can be released to the housing 1 and radiated to the outside of the housing 1. Examples of the metal include aluminum and copper. When considering thermal conductivity, carbon is not limited to metal. As the metal, magnesium that can be injection-molded can be used. When a leakage magnetic field from the magnetic circuit of the drive mechanism 35 affects other devices of the device, it is necessary to devise a method for eliminating the leakage magnetic field. One of them is to make the housing 1 from a magnetic material such as iron. Thereby, the leakage magnetic field is reduced to a considerable level. Further, it may be a ceramic case for use at high temperatures or for special applications.

  The operation of the jet flow generating device 10 configured as described above will be described.

  For example, when a sinusoidal AC voltage is applied to the drive mechanism 35, the diaphragm 33 performs sinusoidal vibration. Thereby, the volume in the chambers 3 and 4 increases or decreases. As the volumes of the chambers 3 and 4 change, the pressures in the chambers 3 and 4 alternately increase and decrease, and along with this, air is alternately discharged as pulsating flows through the flow paths 2a and 2b, respectively. When air is discharged from the flow paths 2a and 2b, the air pressure around the casing 1 and the nozzle body 2 is reduced, so that the surrounding air is caught in the air discharged from the flow paths 2a and 2b, and is synthesized. A jet is generated. This synthetic jet can be cooled by being blown to a heating element (not shown) or a high-heat part. Examples of the heating element include an electronic component such as an IC, a coil, a resistor, or a heat radiating fin (heat sink).

  On the other hand, when air is discharged from the flow paths 2a and 2b, noise due to airflow noise is generated independently of the flow paths 2a and 2b. However, since each sound wave generated in each flow path 2a and 2b is an anti-phase sound wave, it is weakened mutually. Thereby, noise can be suppressed to some extent, and noise reduction can be achieved.

  The jet generating device according to the present embodiment discharges air, but is not limited to air, and may be nitrogen, helium gas, argon gas, or other gases.

  FIG. 5 is a graph showing the relationship between the displacement of the elastic support member 36 and its spring force. In this graph, the magnetomotive force is 10AT. In other words, the “displacement of the elastic support member” is the displacement of the diaphragm 33 from the stationary position of the diaphragm 33 in the Z direction as shown in FIG. 2, and more specifically, in the stationary state of the diaphragm 33. Is the displacement of the diaphragm 33 from the center of gravity position. In this graph, the positive side of displacement is the upward displacement in FIG. 2, and the negative side of displacement is the downward displacement in FIG. In this graph, as shown in FIG. 3, the elastic support member 36 uses an elastic support member 36 whose outer peripheral side is a mountain 36a and whose inner peripheral side is a valley 36b.

  From this graph, the nonlinearity is seen in the spring property. It can be seen that there are two regions, a region where the spring force is very small (plus side) and a region where the spring force is large (minus side). The elastic support member 36 used in this experiment has a crest 36a on the outer peripheral side, but the spring force is reduced on the plus side due to the influence.

  If an elastic support member having a mountain on the inner peripheral side is used, the spring force is large on the plus side and the spring force is small on the minus side. However, since there is an influence of the gravity of the elastic support member and the diaphragm, it is considered that the graph is not completely symmetrical with the graph shown in FIG.

  Here, the stationary position of the diaphragm 33 is lower than the center (0.5 mm in FIG. 6) of the electromagnetic force generated from the drive mechanism 35, for example, the output (displacement) 0 (mm) shown in FIG. However, this is the most characteristic technique of the present embodiment. FIG. 6 is a simulation result of the displacement of the diaphragm 33 when the elastic support member 36 as described above is used. The displacement 0 (mm) is the stationary position (center of gravity position) of the diaphragm 33. As described above, it is desirable that the center position of the electromagnetic force is set to be shifted from the rest position of the diaphragm 33 (the center of gravity position of the diaphragm 33) by a predetermined distance in the vibration direction. Thus, when the diaphragm 33 is driven by the electromagnetic force, the diaphragm 33 tries to move around the center position of the driving force of the magnetic circuit, and the vibration center of the diaphragm 33 is lifted. Here, the vibration center is set to move 0.5 (mm) to the plus side where the spring force is small. Since the spring force is small in this positive region, it is possible to drive with a small current, and as a result, it is possible to reduce power consumption.

  In order to shift the center position of the electromagnetic force, for example, the position in the Z direction where the coil is disposed with respect to the magnetic circuit may be shifted.

  FIG. 7 is a graph showing current values when the diaphragm 33 is driven with a predetermined amplitude by using various types of elastic support members having different shapes and the like and changing the center position of the electromagnetic force in various ways. In FIG. 7, (A) shows that the spring force when the elastic support member moves upward is softer (smaller) than when it moves downward, and the electromagnetic force is above the stationary position of the diaphragm 33. The case where the elastic support member with a center position is used is shown. In (B), the spring force when the elastic support member moves upward is harder (larger) than when the elastic support member moves downward, and the center position of the electromagnetic force is above the stationary position of the diaphragm 33. The case where an elastic support member is used is shown. (C) shows that the spring force when the elastic support member moves upward is softer (smaller) than when it moves downward, and the center position of the electromagnetic force is below the stationary position of the diaphragm 33. The case where a certain elastic support member is used is shown. The graph described in FIG. 6 shows a case where the elastic support member (A) is used. Regarding (C), the power consumption can be reduced compared to (B), but (A) can reduce the power consumption the most.

  From the above, it is possible to reduce the power consumption by using the non-linear characteristic of the spring force and arranging the center of the electromagnetic force on the softer side of the spring.

  Next, a jet generator according to another embodiment will be described. In the following description, it is assumed that the drive mechanism has the same configuration as that of the drive mechanism 35 shown in FIG.

  FIG. 8 is a simulation graph showing the relationship between the thickness of the top yoke 34 in the Z direction and the value of the current flowing through the coil 28. Here, a top yoke 34 having a disk shape is assumed. From the graph of FIG. 8, in order to suppress the power consumption by setting the current value to 0.105 (A) or less, the top yoke 34 may have a thickness of 1.0 to 1.7 (mm). This is the range that can be used as an actual product. The current value is minimized when the thickness of the top yoke 34 is 1.2 (mm).

  FIG. 9 shows the result of analysis of electromagnetic force (Lorentz force) generated in the coil 28 when the coil moves in the height direction (Z direction) using the thickness t of the top yoke 34 as a parameter. The horizontal axis indicates the amount of displacement of the coil, and 0 (mm) is the stationary position of the coil 28. From this graph, it is confirmed that a large force can be obtained in a wide range at t = 1.2 (mm).

  FIG. 10 shows the magnetic flux density generated in the magnetic gap of the magnetic circuit composed of the magnet 27, the top yoke 34, and the bottom yoke 26 with the height position, which is the measurement position, being shown on the horizontal axis. Specifically, the lower end of the vertically extending fine line passing through the center of the coil 28 in FIG. 12B described later is set to 0 (mm) on the horizontal axis in FIG. It can be seen from this graph that the top yoke 34 with t = 1.2 (mm) is the most efficient.

  FIG. 11 shows the BH characteristics of the top yoke 34. As can be seen from FIG. 10, since the top yoke 34 used in this experiment is almost saturated at 2 (T), a magnetic field that generates a maximum magnetic flux of about 2 (T) at the top yoke 34 is obtained. If it is made to generate | occur | produce, a diaphragm can be driven efficiently.

  12 to 14 show the results of magnetic field analysis for each thickness of the top yoke 34. 12 to 14 show the right half of the cross sections of the magnet 27, the top yoke 34, the bottom yoke 26, and the coil 28 in FIG.

12A and 12B show a case where the thickness of the top yoke 34 is appropriate. From FIG. 12A, it can be seen that the magnetic flux emitted from the top yoke 34 is concentrated at the position where the coil 28 is disposed, that is, at the magnetic gap. Further, as shown in FIG. 12B, it can be seen that the top yoke 34 has almost no magnetic flux density in the region of less than 2 (T), and the top yoke 34 is in a state of being hardly saturated. FIG. 12 shows the case where the thickness of the top yoke 34 is, for example, 1.0 to 1.7 (mm). In the figure, regarding the magnetic flux density shown on the left, “xe + 000” is “x × 10 ⁰ ” and “xe−001” is “x × 10 ⁻¹ ”.

  13A and 13B show the case where the top yoke 34 is too thin. From FIG. 13A, it can be seen that the magnetic flux emitted from the magnet 27 leaks from the upper side without entering the top yoke 34 and is not concentrated in the magnetic gap. Further, as shown in FIG. 13B, there are many portions in the top yoke 34 where the magnetic flux density exceeds 2 (T), the top yoke 34 is saturated, and the magnetic flux leaks. I understand.

  14A and 14B show a case where the top yoke 34 is too thick. 14A that the magnetic flux emitted from the magnet 27 passes through the top yoke 34 and is released toward the bottom yoke in a wide range. Since the magnetic flux is released in a wide range, the magnetic flux density has a small value. Further, as shown in FIG. 14B, it can be seen that the top yoke 34 is mostly in a region where the magnetic flux density is less than 1 (T).

  As described above, in the case of the present embodiment, by adjusting the thickness so that the magnetic flux density in the top yoke 34 is less than 2 (T) in many regions, it is possible to create a state that is barely saturated. The magnetic flux can be concentrated and released in a wide range. As a result, the Lorentz force generated by the coil 28 can be maximized. As a result, a large force is generated with a small current, and as a result, power consumption can be minimized.

  FIG. 15 is a graph showing the relationship between the radial position of the disk-shaped top yoke 34 and the magnetic flux density, using the thickness t of the top yoke 34 as a parameter. The “radial position of the top yoke 34” is a radial position in a plane (XY plane) substantially perpendicular to the vibration direction. As shown in FIG. 8, the thickness of the top yoke 34 is 1.0 (mm), 1.2 (mm), 1.4 (mm), and 1 among 1.0 to 1.7 (mm). .6 (mm) was used as a parameter. From this graph, the magnetic flux density is maximum around a radius of 7 mm, and is 1.5 (T) at t = 1.6 (mm) and 2.1 (T) at t = 1.0 (mm). Therefore, in order to suppress the power consumption, as described above, t = 1.0 to 1.7 (mm) and the maximum value of the magnetic flux density is 1.5 to 2.1 (T). do it.

  The present invention is not limited to the embodiment described above, and various modifications are possible.

  As an example of the drive method, for example, the electromagnetic drive method has been described. In particular, for the modes shown in FIGS. 1 to 5, a method using an electrostatic action or a piezoelectric action is also applicable.

  In the above embodiment, the example in which the diaphragm 33 has a flat plate shape has been described. However, the diaphragm 33 may have a three-dimensional shape with a side plate attached thereto, or another three-dimensional shape.

  As electronic equipment on which the jet flow generating device 10 is mounted, a computer (in the case of a personal computer, it may be a laptop type or a desktop type), a PDA (Personal Digital Assistance), an electronic dictionary, a camera, a display Devices, audio / visual devices, projectors, mobile phones, game devices, car navigation devices, robot devices, and other electrical appliances.

It is a perspective view which shows the jet flow generator which concerns on one embodiment of this invention. It is sectional drawing of the jet flow generator shown in FIG. It is an expanded sectional view of a diaphragm and an elastic support member. It is the perspective view which showed the diaphragm, the elastic support member, and the flame | frame separately. It is a graph which shows the relationship between the displacement of an elastic support member, and its spring force. It is a graph which shows the simulation result of the displacement of a diaphragm when the above elastic support members are used. It is a graph which shows an electric current value when a diaphragm is driven with a predetermined amplitude by changing the center position of electromagnetic force using a plurality of types of elastic support members having different shapes and the like. It is a graph of the simulation which shows the relationship between the thickness of the Z direction of a top yoke, and the electric current value sent through a coil. The result of the analysis of the electromagnetic force at the center position in the Z direction of the coil with the thickness t of the top yoke as a parameter is shown. It is a graph which shows the magnetic flux density which generate | occur | produces in the magnetic gap of the magnetic circuit which consists of a magnet, a top yoke, and a bottom yoke, with the horizontal position showing the height position which is a measurement position. It is a graph which shows the BH characteristic of a top yoke. It is a figure which shows the magnetic field analysis result in case the thickness of a top yoke is appropriate. It is a figure which shows the magnetic field analysis result in case the thickness of a top yoke is too thin. It is a figure which shows the magnetic field analysis result in case the thickness of a top yoke is too thick. It is a graph which shows the relationship between the radial position of the disk-shaped top yoke, and magnetic flux density which used the thickness of the top yoke as a parameter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Housing 2 ... Nozzle body 2a, 2b ... Flow path (opening)
DESCRIPTION OF SYMBOLS 10 ... Jet generator 15 ... Vibration actuator 26 ... Bottom yoke 27 ... Magnet 28 ... Coil 33 ... Diaphragm (vibrating body)
34 ... Top yoke 35 ... Drive mechanism 36 ... Elastic support member 36a ... Mountain 36b ... Valley

Claims (7)

A vibration actuator used in a jet generating device that generates a synthetic jet of gas,
A vibrating body,
An elastic support member that supports the vibrating body so as to vibrate, and has a non-linear spring force against the displacement of the vibrating body;
A driving mechanism for driving the vibrating body so that a center position of the driving force in the vibration direction of the vibrating body is deviated by a predetermined distance in the vibration direction from a center of gravity position of the vibrating body in a stationary state. Vibration actuator characterized by The vibration actuator according to claim 1,
The elastic support member has a first spring force at a position displaced by a first distance from the position of the center of gravity to the first side, and a second side opposite to the first side from the position of the center of gravity. A second spring force smaller than the first spring force at a position displaced to the side by the same distance as the first distance;
The driving mechanism drives the vibrating body so that a center position of the driving force is shifted toward the second side. The vibration actuator according to claim 1,
The elastic support member is
A vibration actuator, characterized in that it is a bellows-like member that supports a periphery in a plane substantially perpendicular to the vibration direction of the vibrating body and is provided with one peak and one valley. The vibration actuator according to claim 1,
The drive mechanism is
Magnets,
A cylindrical first yoke that houses the magnet;
A plate-shaped second yoke having a thickness of 1.0 to 1.7 (mm), which is attached to the magnet so as to form a magnetic gap with the first yoke;
A coil disposed in the magnetic gap and connected to the vibrating body;
The vibration actuator, wherein the maximum value of the magnetic flux density at the center position in the thickness direction of the second yoke is 1.5 to 2.1 (T). A vibration actuator used in a jet generating device that generates a synthetic jet of gas,
A vibrating body,
Thickness of 1.0 to 1.7 (mounted on the magnet so as to form a magnetic gap between the magnet, a cylindrical first yoke that accommodates the magnet, and the first yoke) mm) and a coil disposed in the magnetic gap and connected to the vibrating body, and the maximum magnetic flux density at the central position in the thickness direction of the second yoke. And a driving mechanism configured to have a value of 1.5 to 2.1 (T). A housing having an opening and containing a gas inside;
A vibrating body disposed in the housing and discharging the gas through the opening by vibration;
An elastic support member that supports the vibrating body so as to vibrate and has a non-linear spring force relative to the displacement of the vibrating body;
A driving mechanism for driving the vibrating body so that a center position of the driving force in the vibration direction of the vibrating body is deviated by a predetermined distance in the vibration direction from a center of gravity position of the vibrating body in a stationary state. A jet generator characterized by the above. A housing having an opening and containing a gas inside;
A vibrating body disposed in the housing and discharging the gas through the opening by vibration;
Thickness of 1.0 to 1.7 (mounted on the magnet so as to form a magnetic gap between the magnet, a cylindrical first yoke that accommodates the magnet, and the first yoke) mm) and a coil disposed in the magnetic gap and connected to the vibrating body, and the maximum magnetic flux density at the central position in the thickness direction of the second yoke. And a drive mechanism configured to have a value of 1.5 to 2.1 (T).