JPS59112862A - Atomizer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a liquid atomization device that atomizes liquid fuel such as kerosene or light oil, water, medicinal bath liquid, recording liquid, etc. using an electric vibrator. Regarding.

Conventional Structures and Their Problems Various types of liquid atomization devices have been proposed in the past, and many of them use electrical vibrators such as piezoelectric elements.

For example, (1) a piezoelectric element is bolted or glued to a horn-shaped vibrator, the mechanical vibration amplitude of the piezoelectric element is amplified by the horn-shaped vibrator, and a liquid is supplied and dripped onto the amplitude amplifying surface at the tip of the horn. (2) A device that injects an array of ultrasonic atomized particles, which has been put into practical use in inkjet recording devices in recent years, and has a piezoelectric vibrator at one end of the liquid chamber. It has a gold coating and an orifice on the other end.
There is an atomization device that can increase the pressure in a liquid chamber due to the vibration of a piezoelectric vibrator and transmit it to an orifice via all the liquid, and as a result, spray atomized particles from the orifice at a considerable scattering speed.

However, the conventional ultrasonic atomization device described above had various drawbacks.

The atomizing device (1) requires high machining precision for the horn-shaped vibrator and a pot for supplying liquid, so it is expensive, and the method for supplying liquid to the atomizing surface is complicated. there were. In addition, in order to obtain an atomization amount of 20 cc/min, a considerably large power consumption of 5 to 10 watts is required, and
Its atomization ability was also not sufficient.

? )'s atomizer had the advantage of being simple in construction and stable in operation, as is clear from the fact that it is used in inkjet printers. Since the structure is such that the air is transmitted to the orifice through the atomizer, when using a typical liquid that contains a large amount of dissolved air, cavitation bubbles will occur in the liquid chamber, and stable atomization cannot be maintained due to these bubbles. It had the following drawback. Therefore, in order to atomize ordinary liquids, all dissolved air must be removed, making this method extremely lacking in versatility.

OBJECTS OF THE INVENTION It is an object of the invention to provide an atomizing device which eliminates the conventional drawbacks such as and which obtains a sufficient amount of atomization and maintains stable atomization operation.

Structure of the Invention In order to achieve this object, the present invention includes a body provided with a pressurized chamber filled with liquid, a supply section for supplying liquid to the pressurized chamber, and a body configured to face the pressurized chamber. The atomizer is entirely composed of a nozzle part having a nozzle provided in the turret, and an electric vibrator that energizes the nozzle part and vibrates the nozzle.
An atomization device comprising: a current detector that detects a current flowing through the electric vibrator; an amplification section that amplifies a signal from the current detector; and an inductor that transmits a signal from the amplification section to the electric vibrator. It consists of

With this configuration, the electric vibrator forms an electric tank circuit with the inductor, and boosts the voltage supplied to the amplifier section to generate vibrations, which reduces power consumption and also feeds back the signal from the current detector. By amplifying it, a self-excited oscillation system is constructed to automatically track changes in the characteristics of the electrical oscillator9.
Constant atomization operation is maintained. Additionally, during the actual atomization operation, the pressurized chamber acts as a self-sufficient liquid pump by photographing the nozzle plate, making it a conopact atomizer system.

DESCRIPTION OF EMBODIMENTS Referring to FIG. 1, an atomizer which is an embodiment of the present invention will be described. A body 2 fully equipped with a pressurized chamber 1 filled with liquid is fixed to a mounting plate 4 with screws 3.

The liquid enters the pressurizing chamber 1vc through the entire supply pipe 5, and is filled halfway through the vibro for gas discharge during actual atomization. Reference numeral 7 denotes a nozzle portion facing one side of the pressurizing chamber 1, and its outer periphery is joined to the body 2.

A spherical protrusion 8 having a fine nozzle for ejecting droplets is formed at the center of the nozzle portion 7 . Further, an annular electric vibrator, here a piezoelectric element 9, is attached to the nozzle element. This piezoelectric element 9 is a piezoelectric ceramic polarized in the thickness direction, and has electrodes on the joint surface with the nozzle part and on the opposite surface. Reference numeral 10 denotes a lead wire for transmitting a drive signal to the piezoelectric element 9. One side of the lead wire is attached to one side of the piezoelectric element 90, and the other side is connected to the body 2 through a helix 11. When the mechanical vibration of the piezoelectric element 9 is excited by the driving signal, the nozzle part 7 is also urged and vibrated, so that as a result, the liquid in the pressurizing chamber 1 is discharged as atomized particles 12.

Incidentally, the liquid supplied to the pressurizing chamber 1 may be filled halfway with the gas discharge vibrator 6 in the atomizer installation configuration, but as an alternative, the liquid supplied to the pressurizing chamber 1 may be The exhaust vibrator may be empty, and before entering the droplet ejection sequence, negative pressure may be applied, for example, through the exhaust vibrator 6, to fill the pressurizing chamber 1 with liquid and draw the exhaust vibrator halfway up.

According to the latter method, impurities in the liquid solidify in the nozzle, and the problem that droplets cannot be ejected does not occur.

Next, referring to FIG. 2, the driving configuration of the atomizer shown in FIG. 1 will be explained. Reference numeral 13 denotes an amplification section which amplifies one signal from the current detector 14 that detects the entire current flowing through the electric vibrator 9, and transmits one driving signal to the electric vibrator 9 via the inductor L15. There is.

Further, FIG. 3 is an electrical equivalent circuit that approximates the electrical vibrator 9, and has a 160 equivalent parallel capacitance Cs and a 17,1
8. Each series inductance of 19. , a capacitance Go, and a resistance RO. Inductor L15i1 in FIG. 2: Has a series resonance configuration mainly consisting of equivalent parallel capacitance Cs f, and is selected so as to be lower than the resonance frequency of the atomizer. This L and C8 form a Cook circuit, and the drive voltage transmitted from the amplifier 13 is boosted across the electric vibrator 9. Therefore, the oscillation frequency of the 7-driving circuit system determined by L and C8 is set slightly lower than the resonance frequency of the atomizer, and the power consumption of the entire system is low.
Moreover, efficient and stable liquid spraying becomes possible.

Here, the reason why the frequency of the self-oscillation system determined mainly by L, Gsf, and H is set lower than the resonance frequency of the atomizer will be explained with reference to FIG. 4. 4a shows the relationship between frequency and current when a driving voltage is applied to the electrical vibrator 9 without passing through the inductor L, where f=Jr is the electrical resonance frequency and f=far is the electrical resonant frequency. represents the resonant frequency.

f = fm is a frequency approximately halfway between fr and rar, and as is clear from the relationship between the frequency and the atomization amount shown in the same figure, it is the point at which the atomization amount is maximum, and the atomizer mechanical This is the resonance point. It is most efficient to excite the electrical vibrator at this mechanical resonance point. However, when exciting using a self-exciting excavation method with a simple configuration, when the oscillation frequency approaches the resonant frequency, a sudden jump in frequency and power occurs, and stable oscillation may not be possible. In order to avoid this pull-in phenomenon, it is necessary to make the coupling with the drive stage output section sufficiently loose, and the coupling circuit for this requires a complicated configuration and also reduces efficiency. Therefore, as described above, if self-oscillation is performed at a frequency lower than the resonance point, for example, at a point slightly lower than fr, a large amount of atomization can be ensured, and stable oscillation can be maintained.

FIG. 6 shows a specific embodiment of the present invention. The same numbers as last time indicate components having the same function. 20 is a resistor that constitutes a current detector, and this detection signal cap/denosaur 21
The signal is sent to the complete MEC IJ-SEP type amplifier circuit through the inductor 15 and transmitted to the electric vibrator 9 by the operation of the output stage Suinochinog transistors 32 and 33. ing. The amplifier circuit described in @ is composed of resistors 22.23, 24.25, 27, 29.30, transistors 26.31, 32.33, and a switch 28. In this closed loose state, L and the Gs
It forms a self-excited oscillation circuit system with an oscillation period determined by . Furthermore, since the output stage operates in an inverted mode, the loss of the transistor itself is low, and the power consumption of the amplifier section is also low. In this specific embodiment, the structure is complementary, but a structure may be adopted in which, for example, a Swissotenog element is provided for discharging charges from the LCs.

Effects of the Invention According to the atomization device of the present invention, the following effects can be obtained.

(1) In addition to the compact configuration of the atomizer itself, the power consumption of the drive device can be reduced, and the atomizer can achieve lower power consumption, that is, higher efficiency.

(2) Construct an oscillation system that is approximately determined by an equivalent parallel capacitance Cs that changes according to the rate of change in the mechanical resonance point due to the temperature characteristics of the electrical vibrator, and an inductor L that has small temperature characteristics. Moreover, since the frequency is set to be stable for a self-excited oscillation system, the amount of atomization can be ensured, and automatic frequency tracking can be realized with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts of an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of an atomization device of an embodiment of the present invention, and FIG.
The figure is an electrical equivalent circuit diagram of the piezoelectric element, FIG. 4a is a diagram showing the relationship between driving frequency and current, FIG. 1...pressure chamber, 2...body, 6...
... Supply stand 1 (7... Nozzle part, 9... Peephole vibrator, 14... Current detector, 13...
...Amplification section, 16...Inductor 0 Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Figure 10 Figure 2 Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) A body including a pressurizing chamber filled with liquid, a supply section for supplying liquid to the pressurizing chamber, a nozzle section having a nozzle facing the pressurizing chamber, and the nozzle. an atomizer comprising an electric vibrator that fully energizes the nozzle; a torrent flow acclimatizer that detects a current flowing through the electric vibrator of the atomizer; and the current detector. An atomizing device comprising a self-excited oscillator comprising an amplifier that amplifies a signal of the drowsy camera, and an inductor that approximately determines the oscillation period of the system based on the equivalent capacitance of the drowsy camera element. (2) The atomization device according to claim 1, wherein the oscillation frequency of the self-excited oscillator is set lower than the resonance frequency of the electric vibrator.