JP2016010748A - Ultrasonic vibration unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic vibration unit which has a vibration structure suitable for storing a piezoelectric vibrator in a housing.SOLUTION: An ultrasonic vibration unit 10 comprises: a piezoelectric vibrator 12; and a plate 14 to be vibrated which extends in the expansion/contraction direction at the time of electric conduction of the piezoelectric vibrator 12, and in which one part thereof is jointed to the piezoelectric vibrator 12 and a non-junction part 14B not jointed to the piezoelectric vibrator 12 vibrates in its thickness direction due to flexural vibration generated in a junction part 14A with the piezoelectric vibrator 12 on the basis of the expansion/contraction of the piezoelectric vibrator 12.

Description

  The present invention relates to an ultrasonic vibration unit.

  An ultrasonic vibration unit in which a vibration plate is partially overlapped and fixed to one end side of a flat plate piezoelectric vibrator is disclosed (see Patent Document 1).

JP 2006-61785 A

  However, in the above-described conventional example, the housing that accommodates the piezoelectric vibrator is not particularly considered, and the ultrasonic vibration unit is from the viewpoint of preventing aesthetics and adhesion of liquid to the piezoelectric vibrator. It is desirable to accommodate the piezoelectric vibrator in the housing.

  The present invention has been devised in view of the above circumstances, and provides an ultrasonic vibration unit having a new vibration structure that is suitable for housing a piezoelectric vibrator in a housing and has a new vibration structure. Objective.

  The ultrasonic vibration unit according to claim 1 extends in the expansion / contraction direction when the piezoelectric vibrator and the piezoelectric vibrator are energized, and a part of the piezoelectric vibrator unit is joined to the piezoelectric vibrator to extend and contract the piezoelectric vibrator. The non-joint portion that is not joined to the piezoelectric vibrator vibrates in the thickness direction due to flexural vibration generated at the joint portion with the piezoelectric vibrator.

In this ultrasonic vibration unit, the non-bonded portion can be vibrated in the thickness direction due to the flexural vibration generated at the bonded portion between the piezoelectric vibrator and the vibration plate. A sonic vibration unit can be provided.

  According to a second aspect of the present invention, in the ultrasonic vibration unit according to the first aspect of the present invention, the ultrasonic vibration unit includes a holding portion that holds a position that becomes a vibration node during vibration of the vibration plate.

  In this ultrasonic vibration unit, since the holding unit holds the position of the vibration node on the vibration plate, it is possible to suppress a decrease in vibration efficiency of the vibration plate.

  According to a third aspect of the present invention, in the ultrasonic vibration unit according to the second aspect of the present invention, the ultrasonic vibration unit includes a housing that houses the piezoelectric vibrator, and the vibration plate is opposite to the piezoelectric vibrator with respect to the holding portion. The side portion is exposed from the housing.

  In this ultrasonic vibration unit, the piezoelectric vibrator is accommodated in the casing, and a portion of the vibrating plate opposite to the piezoelectric vibrator with respect to the holding portion is exposed from the casing. That is, the piezoelectric vibrator is not exposed to the outside. For this reason, the aesthetics of an ultrasonic vibration unit can be improved.

  According to a fourth aspect of the present invention, in the ultrasonic vibration unit according to the second or third aspect, the vibration plate is bonded to the piezoelectric vibrator and supported by the holding portion; And a perforated plate having a microporous region that is bonded to a support member and atomizes an atomization target by vibration of the piezoelectric vibrator.

  In this ultrasonic vibration unit, since the vibration plate has the support member and the porous plate, the size and thickness of the support member can be freely designed in consideration of flexural vibration and the like. Further, in the vibration plate, since the support member is held by the holding portion, the porous plate is not held by the holding portion. For this reason, the lifetime of a perforated panel can be extended. Furthermore, since the material constituting the perforated plate can be reduced as much as possible, it is advantageous in terms of cost.

According to a fifth aspect of the present invention, in the ultrasonic vibration unit according to any one of the second to fourth aspects, the holding portion is a seal member.
In this ultrasonic vibration unit, since the holding portion is a seal member, it is possible to prevent the atomization target from entering the piezoelectric vibrator side. For this reason, the piezoelectric vibrator can be protected from the atomization target, and the piezoelectric vibrator need not be protected by coating or the like.

  As described above, according to the ultrasonic vibration unit of the first aspect, it is possible to provide an ultrasonic vibration unit having a new vibration structure that is not conventionally provided.

  According to the ultrasonic vibration unit of the second aspect, it is possible to obtain an excellent effect that the vibration efficiency of the vibration plate can be maintained.

  According to the ultrasonic vibration unit of the third aspect, an excellent effect that the aesthetics of the ultrasonic vibration unit can be improved is obtained.

  According to the ultrasonic vibration unit of the fourth aspect, in the vibration plate, it is possible to extend the life of the perforated plate while increasing the degree of freedom in designing the support member, and it is advantageous in terms of cost. An effect is obtained.

  According to the ultrasonic vibration unit of the fifth aspect, since the holding portion is a seal member, the intrusion of the atomization target to the piezoelectric vibrator side can be prevented, and the piezoelectric vibrator can be protected from the atomization target. The excellent effect of being able to be obtained is obtained.

It is typical sectional drawing which shows the ultrasonic vibration unit which concerns on this embodiment. (A) It is a typical sectional view showing the state where the piezoelectric vibrator is not expanded and contracted. (B) It is typical sectional drawing which shows the state which the bending vibration (flexure deformation | transformation) has arisen in the junction part with a to-be-vibrated board by extending a piezoelectric vibrator. It is typical sectional drawing which shows the ultrasonic vibration unit which concerns on 2nd Embodiment. It is typical sectional drawing which shows the ultrasonic vibration unit which concerns on the modification of 2nd Embodiment. It is typical sectional drawing which shows the ultrasonic vibration unit which concerns on 3rd Embodiment. It is typical sectional drawing which shows the ultrasonic vibration unit which concerns on 4th Embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[First Embodiment]
In FIG. 1, an ultrasonic vibration unit 10 according to the present embodiment is used in an atomization device that atomizes a liquid as an example of an atomization target, and includes a piezoelectric vibrator 12, a vibration plate 14, a housing. It has a body 16 and a holding part 18.

  The piezoelectric vibrator 12 is a ceramic ultrasonic vibrator that is vibrated by applying a high-frequency voltage, for example, formed in an annular plate shape. A pair of lead wires (not shown) is attached to the piezoelectric vibrator 12. One lead wire is a hot-side electric wire and is connected to one surface in the thickness direction of the piezoelectric vibrator 12 via a thin film electrode (not shown). The other lead wire is an earth-side wire, and is connected to the other surface in the thickness direction of the piezoelectric vibrator 12 via a thin film electrode (not shown).

  The vibration plate 14 extends in the expansion / contraction direction when the piezoelectric vibrator 12 is energized, and a part thereof is joined to the piezoelectric vibrator 12. The vibration plate 14 has a non-joined portion 14B that is not joined to the piezoelectric vibrator 12 in the thickness direction due to flexural vibration generated in the joined portion 14A with the piezoelectric vibrator 12 based on expansion and contraction of the piezoelectric vibrator 12. It comes to vibrate.

The vibration plate 14 includes a support member 34 and a porous plate 36. The support member 34 is a metal plate that is bonded to the piezoelectric vibrator 12 and formed in a disk shape, for example, and is fixed to one surface of the piezoelectric vibrator 12 in the thickness direction. The thickness of the vibrating plate 14 is set such that the joint 14A with the piezoelectric vibrator 12 is flexibly vibrated by expansion and contraction when the piezoelectric vibrator 12 is energized. Further, the vibration plate 14 is bonded to the entire lower surface of the piezoelectric vibrator 12, and the area of the bonded portion 14A is equal to the area of the lower surface. Therefore, as shown in FIG. 1, the length in the radial direction of the joining portion 14A of the vibration plate 14 is the conventional structure (not shown) in which the vibration plate is bonded to a small part of the lower surface of the piezoelectric vibrator. Compared to, it is secured longer. At the center of the support member 34, for example, a circular through hole 34B is formed. In the vibration plate 14, it is this support member 34 that is held by a holding portion 18 described later.
Note that the vibration plate 14 does not need to be bonded to the entire lower surface of the piezoelectric vibrator 12, and may be bonded within a range in which the joint portion 14 </ b> A with the piezoelectric vibrator 12 can be flexibly vibrated.

  The perforated plate 36 is a member joined to the support member 34. The perforated plate 36 is formed, for example, in a disk shape, and is joined to the periphery of the through hole 34B across the through hole 34B of the support member 34. The perforated plate 36 has a micropore region 24 that atomizes a liquid by the vibration of the piezoelectric vibrator 12. A large number of fine through holes (not shown) are formed in the fine hole region 24. The size of the through hole varies depending on the application and is about 2 to 80 μm. Note that the size of the through hole is not limited to this range. When the vibration plate 14 is vibrated by the operation of the piezoelectric vibrator 12, the micropore region 24 is atomized by passing a liquid (not shown) supplied directly or via liquid supply means to the micropore region 24. It is possible to do.

  At the center of the perforated plate 36, a convex portion 36A is formed that protrudes in a dome shape in one of its thickness directions, for example, upward (in the direction of liquid atomization). The convex portion 36A is located, for example, above the through hole 34B of the support member 34. The micropore region 24 is provided in the convex portion 36A.

  The casing 16 is a member that accommodates the piezoelectric vibrator 12, and is configured using, for example, resin. The housing 16 has a base portion 26 located on one side in the thickness direction of the vibration plate 14 and a lid portion 28 located on the other side in the thickness direction. In the center of the base portion 26, a through portion 26A for passing a liquid (not shown) is formed. The base portion 26 and the lid portion 28 are not in contact with the piezoelectric vibrator 12.

  In the center of the lid portion 28, a through portion 28A for exposing, for example, the fine hole region 24 of the vibration plate 14 is formed. The through portions 26A and 28A have the same inner diameter and are arranged coaxially. The periphery of the through portion 28A in the lid portion 28 is an annular thick portion 28B. The thick part 28B is a part formed thicker than the surrounding general part 28C. The thick portion 28B protrudes toward the vibration plate 14 (inner surface side of the base portion 26) on the radially inner side from the inner peripheral surface of the piezoelectric vibrator 12. On the outer surface of the lid portion 28, the thick portion 28B and the general portion 28C are flush with each other and have no boundary. Similarly, the base portion 26 is provided with a thick portion 26B and a general portion 26C.

  The holding portion 18 is a member that holds a position that becomes a vibration node N when the vibration plate 14 vibrates. The holding portion 18 is provided between the housing 16 and the vibration plate 14, holds the vibration plate 14 at a position away from the piezoelectric vibrator 12, and the exposed side of the vibration plate 14 and the piezoelectric vibrator. It is divided between the 12 side. In other words, the vibrating plate 14 is exposed from the housing 16 at a portion opposite to the piezoelectric vibrator 12 with respect to the holding portion 18, specifically, a central portion where the porous plate 36 is located. Specifically, the holding portion 18 is, for example, a ring-shaped seal member, and is provided between the thick portion 26B of the base portion 26 and the vibration plate 14 and between the thick portion 28B and the vibration plate 14 of the lid portion 28. Are provided respectively. In order to schematically show that the holding portion 18 holds the vibration node N, the holding portion 18 is drawn in an edge shape having a triangular cross section in the drawing. When the holding portion 18 has an edge shape, a region where the holding portion 18 abuts on the vibration plate 14 can be narrowed, and a decrease in vibration efficiency of the vibration plate 14 can be suppressed. When an O-ring is used as the holding unit 18, the cross section of the holding unit 18 is substantially circular. The vibration node N is a portion where the amplitude during vibration is substantially zero. The position of the node N can be easily obtained by actually vibrating the vibrating plate 14 or the like.

  The ultrasonic vibration unit 10 is configured to flexibly vibrate the vibration plate 14 based on expansion and contraction of the piezoelectric vibrator 12. In the present embodiment, the piezoelectric vibrator 12 expands and contracts in the radial direction, and the vibration plate 14 flexes and vibrates in the thickness direction.

(Function)
This embodiment is configured as described above, and the operation thereof will be described below. First, referring to FIG. 2, the flexural vibration (deflection deformation) of the vibration plate 14 by the piezoelectric vibrator 12 will be described. 2A and 2B, for simplicity, the vibration plate 14 is bonded to the entire lower surface of the piezoelectric vibrator 12, and the lengths of the piezoelectric vibrator 12 and the vibration plate 14 are drawn to be equal to each other. ing. 2A shows a state where the piezoelectric vibrator 12 is not expanded or contracted.
As shown in FIG. 2B, when the piezoelectric vibrator 12 is extended, the piezoelectric vibrator 12 is integrated with the vibration plate 14 via the joint 14A. The plate 14 is bent and deformed (curved) integrally.
When the piezoelectric vibrator 12 is contracted, the piezoelectric vibrator 12 and the vibration plate 14 are integrally deformed (curved) in a direction opposite to that when the piezoelectric vibrator 12 is extended.

  Thus, when the piezoelectric vibrator 12 expands and contracts, the joint 14A of the vibration plate 14 is bent and deformed integrally with the piezoelectric vibrator 12, so that the vibration plate is expanded by the expansion and contraction of the piezoelectric vibrator 12 when energized. The 14 joining portions 14 </ b> A are flexibly vibrated integrally with the piezoelectric vibrator 12. As shown in FIG. 1, the flexural vibration causes the non-bonded portion 14 </ b> B of the vibrating plate 14 that is not bonded to the piezoelectric vibrator 12 to vibrate in the thickness direction. The perforated plate 36 in the vibration plate 14 is located at the antinode (position where the amplitude is the largest) of vibration. A liquid (not shown) supplied to the perforated plate 36 is atomized when passing through the micropore region 24 due to the vibration of the perforated plate 36. Since the micropore region 24 is formed on the convex portion 36A that is raised in a dome shape in the porous plate 36, the atomization efficiency in the case of atomizing the liquid can be improved.

  In this ultrasonic vibration unit 10, the piezoelectric vibrator 12 is accommodated in the housing 16, and a portion of the vibration plate 14 opposite to the piezoelectric vibrator 12 with respect to the holding portion 18 is exposed from the housing 16. ing. That is, the piezoelectric vibrator 12 is not exposed to the outside. That is, the holding portion 18 partitions the exposed side of the vibration plate 14 and the piezoelectric vibrator 12 side. For this reason, the aesthetics of the ultrasonic vibration unit 10 can be improved.

  In the ultrasonic vibration unit 10, the vibration plate 14 includes the support member 34 and the porous plate 36. Therefore, the size and thickness of the support member 34 can be freely designed in consideration of flexural vibration and the like. Can do. Further, since the support member 34 is held by the holding portion 18 in the vibration plate 14, the porous plate 36 is not held by the holding portion 18. For this reason, in the vibration plate 14, the life of the porous plate 36 can be extended while increasing the degree of freedom in designing the support member 34. Moreover, since the material which comprises the perforated panel 36 can be reduced as much as possible, it is advantageous also in terms of cost.

  In the present embodiment, since the holding unit 18 holds the position of the vibration node N in the vibration plate 14, it is possible to suppress the holding unit 18 from interfering with the vibration of the vibration plate 14 as much as possible. it can. For this reason, it is possible to suppress a decrease in vibration efficiency of the vibration plate 14.

  Further, in the ultrasonic vibration unit 10, since the holding portion 18 is a sealing member, when the liquid is atomized by the ultrasonic vibration unit 10, the exposed side of the vibration plate 14 is not exposed, that is, the piezoelectric vibrator. Intrusion of liquid into the 12 side can be prevented. Since the piezoelectric vibrator 12 can be protected from the liquid, the piezoelectric vibrator 12 need not be protected by a coating or the like.

[Second Embodiment]
In FIG. 3, in the ultrasonic vibration unit 20 according to the present embodiment, a convex portion 34 </ b> A that protrudes at the center of the support member 34 in the vibration plate 14 in one of the thickness directions, for example, upward (in the direction of liquid atomization). Is formed. The perforated plate 36 is joined to the convex portion 34A.

  In the present embodiment, since the flexural rigidity of the convex portion 34A in the support member 34 is relatively high, when the support member 34 undergoes flexural vibration, the convex portion 34A is vibrated while suppressing the bending deformation of the convex portion 34A. Can do. Since the porous plate 36 is joined to the convex portion 34A, bending deformation of the porous plate 36 is also suppressed. For this reason, the durability of the porous plate 36 can be improved.

  Since other parts are the same as those in the first embodiment, the same parts are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

[Modification of Second Embodiment]
In FIG. 4, in the ultrasonic vibration unit 20 </ b> A according to the present embodiment, the perforated plate 36 has a flat shape without the convex portion 36 </ b> A protruding in the above-described dome shape, and a through hole 34 </ b> B formed in the center of the support member 34. A fine pore region 24 is located above.
Since other parts are the same as those of the second embodiment, the same parts are denoted by the same reference numerals and description thereof will be omitted.

[Third Embodiment]
In FIG. 5, in the ultrasonic vibration unit 30 according to the present embodiment, the vibration plate 14 has a rectangular shape in plan view, for example, and the piezoelectric vibrator 12 having a substantially rectangular shape in plan view has a longitudinal direction of the vibration plate 14. It is joined to one end. Since the vibration plate 14 is rectangular, the holding portions 18 are provided on the side closer to and far from the piezoelectric vibrator 12. Between the two holding parts 18, the penetration part 26A of the base part 26 and the penetration part 28A of the cover part 28 are located. The holding portion 18 is provided at a position where the vibration plate 14 becomes a vibration node N.

  In the ultrasonic vibration unit 30, the piezoelectric vibrator 12 is bonded to one end in the longitudinal direction of the vibration plate 14, but the piezoelectric vibrator 12 is not exposed to the outside. Moreover, since the holding part 18 is provided in the position used as the vibration node N in the vibrating plate 14, it can suppress as much as possible that this holding part 18 becomes the obstruction of the vibration of the vibrating plate 14. FIG. . For this reason, the aesthetics of the ultrasonic vibration unit 30 can be improved while maintaining the vibration efficiency of the vibration plate 14.

  Since other parts are the same as those in the first embodiment, the same parts are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

[Fourth Embodiment]
In FIG. 6, in the ultrasonic vibration unit 40 according to the present embodiment, the vibration plate 14 is made of, for example, a disk-shaped metal plate. At the center of the vibrating plate 14, a convex portion 14 </ b> C is formed that protrudes in a dome shape in one of the thickness directions, for example, upward (in the direction of liquid atomization). The micropore region 24 is provided in the convex portion 14C.

  In the present embodiment, a dome-like convex portion 14C is formed on the vibration plate 14, and the liquid is easily constrained by the concave portion on the lower surface side of the convex portion 14C. Since the fine hole region 24 for atomizing the liquid is provided in the convex portion 14C, the atomization efficiency when the liquid is atomized by the ultrasonic vibration unit 40 can be improved.

  Since other parts are the same as those in the first embodiment, the same parts are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

[Other Embodiments]
As mentioned above, although an example of embodiment of this invention was demonstrated, embodiment of this invention is not limited above, In addition to the above, in a range which does not deviate from the main point, it can implement variously. Of course there is.

  For example, the configuration of the vibration plate 14 is not limited to that described in each embodiment. The vibration plate 14 may be obtained by bonding a flat perforated plate as shown in FIG. 4 to a flat support member 34 (FIG. 1). Further, the vibration plate 14 may be formed flat by removing the convex portion 14C from the vibration plate 14 shown in FIG. The vibration plate 14 does not need to have the fine hole region 24.

The holding unit 18 holds the position where the vibration plate 14 becomes the vibration node N. However, the holding unit 18 is not limited to this, and if the influence on the vibration efficiency of the vibration plate 14 is small, the holding unit 18 may vibrate. It may be set at a position other than the node N.
Further, in any of the above-described embodiments, the end of the piezoelectric vibrator 12 and the end of the vibration plate 14 are exemplified, but the end of the vibration plate 14 is the same as that of the piezoelectric vibrator 12. It may protrude slightly from the end.
Furthermore, in any of the above-described embodiments, the ultrasonic vibration unit is applied to a mesh atomizer, but the application range of the ultrasonic vibration unit according to the present invention is arbitrary. Moreover, although the liquid was mentioned as an example of the atomization object, the atomization object is not restricted to a liquid, A powder, a viscous body, etc. may be sufficient.

DESCRIPTION OF SYMBOLS 10 Ultrasonic vibration unit 12 Piezoelectric vibrator 14 Vibrating plate 14A Joining part 14B Non-joining part 16 Case 18 Holding part 20 Ultrasonic vibration unit 20A Ultrasonic vibration unit 24 Micropore area 30 Ultrasonic vibration unit 34 Support member 36 Porous Plate 40 Ultrasonic Vibration Unit N Section

Claims (5)

A piezoelectric vibrator;
Extending in the expansion and contraction direction when the piezoelectric vibrator is energized, a part of which is joined to the piezoelectric vibrator, and based on the expansion and contraction of the piezoelectric vibrator, the flexural vibration generated at the joint with the piezoelectric vibrator, A vibration plate in which a non-bonded portion that is not bonded to the piezoelectric vibrator vibrates in the thickness direction;
An ultrasonic vibration unit.   The ultrasonic vibration unit according to claim 1, further comprising a holding portion that holds a position that becomes a vibration node when the vibration plate is vibrated. A housing for housing the piezoelectric vibrator;
The ultrasonic vibration unit according to claim 2, wherein a portion of the vibration plate opposite to the piezoelectric vibrator with respect to the holding portion is exposed from the housing.   The vibration plate has a support member that is bonded to the piezoelectric vibrator and held by the holding portion, and a micropore region that is bonded to the support member and atomizes the atomization target by vibration of the piezoelectric vibrator. The ultrasonic vibration unit according to claim 2, further comprising a perforated plate.   The ultrasonic vibration unit according to claim 2, wherein the holding portion is a seal member.

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