JPS58180259A - Atomizing device - Google Patents

Abstract

PURPOSE:To enable the spraying and atomizing of the liquid packed in a pressurizing chamber from a nozzle by transmitting the oscillation in parallel with a nozzle plate of an electrical oscillator to the nozzle plate by changing the oscillation direction thereof. CONSTITUTION:A nozzle 35 of a nozzle plate 39 is so positioned to face a pressurizing chamber 29 to be filled with liquid, and an electrical oscillator 36 having an aperture part 38 is provided. The oscillator 36 and the plate 39 are adhered in the position where the nozzle 35 faces the part 38, and where the oscillator 36 oscillates in parallel with the plate 39. Further, the oscillation direction of the oscillator 36 is changed by a direction changing and transmission part 42 so as to transmit the oscillation of the oscillator 36 to the plate 39 facing the part 38. In other words, the deflective oscillation of the plate 39 facing the part 38 is excited extremely efficiently and stably, by which the nozzle 35 is oscillated. As a result, the liquid filled in the chamber 29 is injected from the nozzle 35 and is thereby atomized.

Description

[Detailed description of the invention] The present invention applies to liquid fuels such as kerosene and light oil, water, and chemical solutions.

Regarding an atomization device for atomizing various liquids such as recording liquids such as ink for various purposes, more specifically, it is an atomization device that uses ultrasonic vibration of an electric vibrator such as a piezoelectric vibrator. This invention relates to a so-called ultrasonic atomization device that atomizes liquid.

Conventionally, various types of atomizing devices of this type have been proposed and put into practical use or considered for practical use.

The most typical ultrasonic atomization device transmits ultrasonic vibrations from a piezoelectric vibrator, magnetostrictive vibrator, etc. to a horn-shaped amplitude-increasing vibrator, and emits liquid onto the vibration amplitude-increasing surface at the tip of the horn. It is dripped and atomized using a pump, etc.

The second ultrasonic atomization device is equipped with a piezoelectric vibrator on the bottom of the liquid tank, and concentrates ultrasonic energy near the liquid surface of the liquid tank to generate a liquid column, which is a type of cavitation phenomenon near the liquid surface. It atomizes using water, and has been put into practical use in humidifiers, for example.

The third ultrasonic atomization device is one that has recently been used in ink atomization devices for recording devices such as facsimile machines, and as shown in FIG.
A piezoelectric vibrator 3 is provided at the other end, and the piezoelectric vibrator 3
The pressure increase in the liquid chamber 1 due to the ultrasonic vibration of the orifice 2
The transmission concentrates near the ink, and the pressure rise causes the ink fine particles 4 to be ejected and atomized. Various atomizing devices having similar configurations have been proposed.

However, these conventional atomization devices have the following drawbacks, which pose a major problem in their application.

The first conventional ultrasonic atomization device requires a full amplitude horn, and requires high processing precision and troublesome maintenance of fixing conditions to ensure stable vibration. This requires a liquid supply device, which has forced the entire device to be larger and more expensive.Also, the energy required for atomization is approximately 20 cr4/min. It takes about 10 watts to obtain the same, and the atomization performance such as the particle size of the atomized particles, their uniformity, and the atomization pattern stability is not sufficient.

The second ultrasonic atomization device was characterized by being able to obtain extremely small atomized particles and not damaging the liquid supply means such as a pump. A high frequency of about 2 Mtlz is required,
Moreover, it required about 60 watts of power to obtain an atomization amount of about 2 occ/min. Therefore, it has serious disadvantages in that it emits extremely large amounts of unnecessary radiation and is highly likely to cause radio wave interference, and its drive circuit has to be extremely expensive. In general, the vibration state changes significantly depending on the temperature of the liquid and the distance between the liquid surface and the piezoelectric vibrator.
As a result, it was extremely difficult to maintain stable atomization operation.

The third ultrasonic atomizer has a small rust particle size.

It has the advantage of excellent uniformity, no need for liquid supply means such as a pump, and extremely low power consumption. Therefore, cavitation bubbles are generated in the ink chamber 1 due to the ultrasonic waves. For this reason, it is necessary to remove dissolved air within the ink, which is extremely troublesome. Therefore, in order to atomize a general liquid containing a large amount of dissolved air, an atomization device C that has a device for removing dissolved air is required, which increases the size and cost of the entire device. It was something I was forced to do.

The present invention aims to provide an ultrasonic atomization device that eliminates the above-mentioned conventional drawbacks.

The first object is to provide an atomizing device which is extremely simple and compact in construction and therefore extremely inexpensive.

The second object is to provide an atomization device that consumes very little power, has excellent atomization performance such as atomization, uniformity of particle size, etc.

The third objective is to realize an atomization device that can extremely stably atomize even a liquid containing a large amount of dissolved air.

In order to achieve this object, the present invention has the configuration described below.

That is, it includes a pressurizing chamber for filling with liquid, a nozzle plate having a nozzle facing the pressurizing chamber, and an electric vibrator having an opening, the nozzle facing the opening. In this way, the nozzle plate and the electric vibrator are bonded together, the vibration direction of the electric vibrator is parallel to the nozzle plate, and the vibration of the electric vibrator is A direction changing transmitting section is provided which changes the direction 'kf and transmits the signal to the nozzle plate facing the opening.

With this configuration! l1% The bending vibration of the nozzle plate facing the opening can be extremely efficiently and stably excited to vibrate the nozzle, and as a result, the liquid filled in the pressurizing chamber can be transferred to the nozzle. This makes it possible to inject and atomize the particles.

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

FIG. 2 is a sectional view showing the construction of an oil hot air blower to which the atomization device of one embodiment of the present invention is applied.

In the figure, 6 is the hot air fan case, and 6 is the operation ￥A
%7 is a control section.

Kerosene, which is a fuel, is sent from a tank 8 through a pipe 9 to a repeller 1o for controlling the liquid level at a constant level. Repeller 1
0 and the atomizing section 11 are connected by a pipe 12, and the atomizing section 11
It is further connected by a pipe 13 to a negative pressure generating section 16 near an orifice 16 provided upstream of the combustion fan 14. Since the liquid level of kerosene is controlled by the leveler 1o to the liquid level position when the operation is stopped, the liquid level in the pipe 12 is the liquid level B in the figure.

When the operation command from the operation unit 6 is given to the control unit 7, the control unit 7 starts the motor 17 that drives the combustion fan 14t. Therefore, combustion air is sucked in from the intake port 18 through the orifice 16, and a negative pressure of, for example, Th -30 to -50fffflAq is generated in the negative pressure generating section 16. Then, the swirler 19 generates a swirling air flow. It is sent to the atomization mixing chamber 20 as shown by the arrow in the figure, and is then sent to the combustion chamber 21.
All of the air passes through and is exhausted from the exhaust pipe 22.

The atomization part 11 fixed to the wall surface 23 of the atomization mixing chamber 2o is
Although kerosene is not filled when the operation is stopped, the liquid level B in the pipe 12 increases due to the negative pressure generated in the negative pressure generating section 16.
rises to the position of the liquid level C in the pipe 13 and is balanced, and as a result, it is completely filled with kerosene. This filling of the kerosene into the atomizing section 11 is due to the increase in the rotational speed of the combustion fan 14. Since this is carried out along with an accompanying increase in the negative pressure of the negative output generation section 16, the so-called pre-purge time of the combustion fan 14 can be used as the filling time into the atomization section 11.

Next, the control unit 7 activates all the igniters 24 and automatically starts the atomizing unit 1.
1. Start all. Therefore, from the atomizing section 11, the atomizing mixing chamber 2
The atomized particles 26 are sprayed onto 0. The atomized particles 26 are then ignited by the igniter 24 to form a flame 26 and burn.

The flame state is detected by the flame state sensor 27, and upon receiving the ignition detection signal, the control section 7 stops the operation of the igniter 24. In addition.

28 is a convection fan.

When the atomizing device of one embodiment of the present invention is applied to construct a hot air fan in this way, the structure of the hot air fan becomes extremely simple and compact.

Next, the atomizing section 11 will be explained in more detail. Third
The figure is a sectional view showing a more detailed configuration of the atomizing section 11, and the same reference numerals as in FIG. 2 are equivalent. The atomizing unit 11 is configured as a structure that includes a bodini 3o that has a cylindrical pressurizing chamber 29 with a diameter of 10 to 16 mm and a depth of about 2 to 10 mm. It is fixed to the wall surface 23 of the mixing chamber. The opening surface of the pressurizing chamber 29 (
The nozzle plate 33 is bonded with an adhesive layer 34 so as to close the circular shape. The nozzle plate 33 has a thickness of 30 to 1oOμ
A metal plate with a diameter of 30 to 1 mm is placed in the center
A plurality of nozzles 36 having a diameter of about 00 μm are provided. The nozzle plate 33 has a diameter of 10 to 15'mm and a thickness of 0.5mm.
A piezoelectric vibrator 36 of ~2 mm and 11 degrees is bonded with an adhesive layer 37. The center part of the piezoelectric vibrator 36 has a diameter of 2~
An opening 38 of about 5+11[D is provided, and the nozzle plate 3
3 faces this opening 38 and this opening 38
A nozzle 36 is provided on a nozzle plate 39 facing 1.
A curved surface portion 4o is provided to disperse the spraying direction of the atomized particles 25 (711) as shown in the figure. Therefore, the nozzle 36 is configured so as to face both the opening 38 of the piezoelectric vibrator 36 and the pressurizing chamber 29. The surface 41 of the opening 38 of the piezoelectric vibrator 36 and the portion 39 of the nozzle plate facing the opening 38 are coupled by a vibration direction conversion/transmission section 42 formed of the same adhesive material as the adhesive layer 37. V
As will be described later, the piezoelectric vibrator 36 is configured to effectively transmit vibrations of the piezoelectric vibrator 36 to a nozzle plate 39 facing the opening 38.

43 and 44 are electrodes, which are metal layers such as silver or nickel deposited or baked on both sides of the piezoelectric vibrator 36.

A lead wire 46 is connected to the electrode 43, and a lead wire 46 is connected to the electrode 44 through the nozzle plate 33 and the body 30. a.

The piezoelectric vibrator 36 is configured to be supplied with an alternating current voltage such as b or c. The supply voltage can be supplied as an alternating voltage as shown in FIG. 5a or b depending on the amount of atomization to be atomized, the timing, etc.

The piezoelectric vibrator 36 has 5 parts as shown in a perspective view in FIG.
It is a piezoelectric ceramic in the shape of a ring, and is polarized so that it undergoes expansion and contraction strain in the radial direction as shown by the arrows in the figure, depending on the applied voltage.

In other words, it is a piezoelectric vibrator that utilizes a transverse effect.

The atomizing operation caused by the vibration of the piezoelectric vibrator 36 will be further explained.

7 &-"+4 is an enlarged sectional view of the vicinity of the opening 38 of the piezoelectric vibrator 36 in FIG. 3, and the same reference numerals as in FIG. 3 are equivalent.

In FIG. 7a, the piezoelectric vibrator 36 expands and contracts in its radial direction when supplied with an alternating current voltage as shown in FIGS. 4a to 4C, as explained in FIG. 6. When a positive half-cycle voltage is applied, the piezoelectric vibrator 36 tends to be displaced in the direction of its opening a8 in FIG. 7a, but the electrode 44 side
Since it is adhered to the nozzle plate 33 with the adhesive layer 37,
Only a small displacement occurs compared to the electrode 43 side. Therefore, as shown by the arrows in FIG. 7, the displacement distribution becomes larger toward the electrode 43. This displacement is transmitted to the nozzle plate 39 facing the opening part 38 of the vibration direction conversion transmission part 42, causing the nozzle plate 39 to undergo a deflection displacement with the point P as the fulcrum.

That is, one point Q is displaced downward as a point pl fulcrum and a point Ri as a driving source. Conversely, a negative half-cycle voltage causes the piezoelectric vibrator 36 to undergo a displacement opposite to that described above, and the direction of movement of point R9 to point Q relative to point P is also opposite to that described above.

FIG. 7C shows a model of this situation, where the strain generated by the piezoelectric vibrator 36 causes the point R to change to R' and R.
As shown in the figure, the sword moving parallel to the nozzle plate 33 is moved to the position # of the vibration direction conversion transmission unit 42 at the points 'Q' and 'Q'.
The nozzle plate 3 facing the opening 38 is moved to the position of
9, the nozzle plate 3 as shown by the arrow in the figure
This shows that it is possible to excite the flexural vibration of 9.

In this way, the flexural vibration of the nozzle plate 39 facing the opening 38 can be very easily activated and caused by the excitation of the piezoelectric vibrator 36 vibrating parallel to the nozzle plate 33. Note that, as is clear from the above description, the outer periphery of the nozzle plate 33 does not necessarily correspond to the nozzle plate 3 facing the opening 38.
It does not have to be the same member as 9.

FIGS. 8a and 8b show the above-mentioned flexural vibration of the nozzle plate 39, and this flexural vibration causes the nozzle 36 to vibrate.

By the vibration of the nozzle 36 shown in FIGS.
The atomized particles 26 are sprayed from the nozzle 35 as shown in the figure. In the state shown in FIG. 8, a sudden pressure rise occurs near the nozzle 36 in the pressurizing chamber 29, and the atomized particles 25 are atomized from the nozzle 35 due to this pressure rise. In the state shown in FIG. 8, the pressure in the vicinity of the nozzle 35 decreases, but air does not flow in from the nozzle 36 due to the surface tension of the kerosene, and as a result, the kerosene is sucked through the pipe 12. It can exhibit self-sufficient pumping action.

As is clear from the above description, one deflection of the nozzle plate 39 causes one atomized particle to be atomized per nozzle 36 in one cycle of the AC voltage that can be applied to the piezoelectric vibrator 36. Depending on the diameter of the atomized particle 36, it is possible to produce atomized particles having a uniform and small particle size.Moreover, the scattering direction of the atomized particles is extremely stable. The injection timing and spray amount can be controlled freely by intermittent supply of applied voltage as shown in Fig. 6 f and b.

The input power to the piezoelectric vibrator 36 required to obtain an atomization amount of about 20 cc/min is only 0.1 degree, which is extremely low power consumption and has excellent atomization characteristics.

A compact atomization device having a self-contained pumping action can be realized.

As is clear from the explanations of FIGS. 7 a to c1 and FIGS. 8 a and b, the rate at which the vibration energy of the piezoelectric vibrator 36 is directly applied to the liquid oil in the pressurizing chamber 29 is extremely high. The ultrasonic vibration energy based on the vibration of the nozzle 35 is only applied to the kerosene in the pressurizing chamber 29 only in the vicinity of the nozzle 35 . Therefore, dissolved air hardly becomes bubbles due to ultrasonic cavitation in the pressurizing chamber 29, and even if small bubbles occur, they are very close to the nozzle 36, so they are not ejected from the nozzle 36.
However, the bubbles do not grow to a size that would affect the atomization operation. Therefore, even liquids such as kerosene containing a large amount of dissolved air can be atomized extremely stably.

FIG. 9 a%-el shows another configuration example centered on a vibration direction conversion transmission section 42 that converts the vibration direction of the piezoelectric vibrator 36 and transmits it to the nozzle plate 39 facing the opening 38. The same reference numerals as in Fig. 3 correspond to those shown in Fig. 9. In Fig. 9, the vibration direction conversion and transmission section 42 is configured to connect a part of the surface 41 of the opening 38 and the nozzle plate 39. In this example, the nozzle plate 39 is flat, but the same atomizing operation as shown in FIG. 3 can be realized. Then, the atomized particles 26 are ejected from the nozzle 35 in a straight line.

The figure also shows that the vibration direction conversion transmission section 42 is connected to the adhesive layer 37.
It is advantageous in that the properties of the adhesive material can be independently selected for each of the adhesive layer 37 and the vibration direction conversion/transmission section 42.

In Figure C, an electrode 47 is also provided on a part of the surface 41 of the opening 38 and combined with the electrode 44.

The adhesive layer 37 and the vibration direction variable transmission section 42 are made of a metal adhesive material such as solder or brazing material, and the adhesive layer 3
7 and the vibration direction conversion transmission section 42 can be significantly improved in environmental and temporal reliability.

Figure d shows a structure in which the electrode 47 shown in figure C covers the entire surface 41 of the opening 3B.

In addition, in FIG. It is configured to be coupled to the nozzle plate 39, and has the advantage that the shape of the vibration direction conversion and transmission section 42 can be arbitrarily configured.

In addition, in FIGS. d and e, the adhesive layer 37 is applied to the entire nozzle plate 33 on the entire lower surface (that is, the electrode 44) of the piezoelectric vibrator 6.
Although it is not configured to be fixed (adhered) to the outer circumference of the nozzle plate 39 facing the opening 38 of the piezoelectric vibrator 36,
Since the structure is such that it is bonded to the piezoelectric vibrator 36, it is basically possible to excite the vibration state shown in FIG. 7 IL%c.

From the electrical characteristics of the piezoelectric vibrator 36.

Adhesive structures such as those shown in Figures d and e may be desirable in some cases.

10a and 10b are examples in which the piezoelectric vibrator 36 is configured to vibrate due to a longitudinal effect, and the same reference numerals as in FIG. 3 are equivalent.

In FIG. 10a, the piezoelectric vibrator 36 is distorted in the direction of the applied electric field as indicated by the arrow in the figure in response to the AC voltage supplied between the electrodes 43 and 44. 〇6o is an electrode;
The nozzle plate 33 is bonded to the nozzle plate 39 and the piezoelectric vibrator 36t by the adhesive layer 37 made of solder and the vibration direction conversion transmission part 42.0 and 51 are non-conductive adhesives. In order to maintain insulation between the electrode 43 of the piezoelectric vibrator 36 and the nozzle plate, a step is provided as shown in the figure.

In the figure, the adhesive layer 37 is made thicker, the nozzle plate 33 has a flat plate structure, and the insulation between the electrode 43 and the nozzle plate 33 is increased.

As shown in FIGS. 9 and 10, the embodiment of the present invention can adopt various configurations; If the structure is such that the bending vibration of the nozzle plate 39 facing the nozzle plate 38 is excited, and the vibration direction conversion transmission section 42t is provided so that the bending vibration of the nozzle plate 39 can be excited extremely easily, It is possible to obtain the same effects as the above-described embodiment of the present invention. In other words, the flexural vibration of the vibration direction conversion transmission section 42 and the nozzle plate 39 can be excited extremely efficiently and stably.

As described above, according to the present invention, a nozzle plate provided with a nozzle facing a pressurized chamber fully filled with liquid and an electric vibrator having an opening are arranged such that the nozzle faces the opening. Because it is bonded and configured to change and transmit vibration direction,
It is extremely simple and compact in configuration, and therefore low in price, and despite its low power consumption, it is able to excite extremely stable flexural vibrations of the nozzle plate, thus providing excellent atomization performance. It is possible to provide an atomization device that can. In particular, since the nozzle plate only near the nozzle undergoes strong ultrasonic vibration, even various common liquids containing a large amount of dissolved air are not affected by cavitation and air bubbles and are extremely stable. All atomizing devices capable of realizing an atomizing operation can be provided. Furthermore, the controllability of the generated atomized particles is extremely high, and in combination with the above-mentioned effects, various applications are possible, and its industrial value is extremely large.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional ultrasonic atomizer, Fig. 2 is a sectional view showing the configuration of a hot air fan to which an atomizer according to an embodiment of the present invention is applied, and Fig. 3 is a sectional view of the same atomizer. FIG. 4 arc is a voltage waveform diagram showing an example of the drive voltage waveform of the piezoelectric vibrator of the atomization device, and FIGS. 6 a and b are voltage waveforms supplied to the piezoelectric vibrator. A waveform diagram, FIG. 6 is a perspective view of the piezoelectric vibrator, and FIGS. 7 a, b, and c are explanatory diagrams of vibration transmission from the piezoelectric vibrator to the nozzle plate by the vibration direction conversion and transmission section,
Figures 8a and 8b are explanatory diagrams of bending vibration of the nozzle plate of the same atomizing device, and Figures 9a, b, c, d, and ss are other examples of the piezoelectric vibrator and nozzle plate of the same atomizing device. FIGS. 10a and 10b are sectional views showing still another embodiment of the same piezoelectric vibrator and nozzle plate. 29... Pressure chamber, 33.39... Nozzle plate. 36... Nozzle, ae... Electric vibrator, 38... Opening, 42... Vibration direction conversion transmission section. Name of agent: Patent attorney Toshio Nakao et al.
Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 IQ) (b) Figure 9 Figure 10 Figure 33;j/3q

Claims (1)

[Scope of Claims] (Moon) A pressurized chamber filled with a liquid, a nozzle plate having a nozzle facing the pressurized chamber, and an electric vibrator having an opening, the nozzle being connected to the opening. bonding the electric vibrator and the nozzle plate so as to face the
The electric plate mover is configured to vibrate parallel to the nozzle plate. The atomization device further includes a direction conversion transmission section that converts the vibration direction of the electric vibrator and transmits the vibration to a nozzle plate facing the opening. (2) The atomization device according to claim 1, wherein the direction conversion transmission section is made of an adhesive material that adheres the electric vibrator and the nozzle plate. (3) The electric vibrator is composed of a plate-shaped piezoelectric vibrator. Claims: Electrodes are provided on the surface of the piezoelectric vibrator on the side to be adhered to the nozzle plate and on at least a portion of the surface of the opening, and the electrodes and the nozzle plate are bonded to each other with a metal material such as solder. The atomization device according to item 1 or 2.