JPS59154159A - Atomizer - Google Patents

Abstract

PURPOSE:To change the oscillation frequency in an oscillation driving part in follow up to the temp. deviation in a mechanical resonance point by providing a temp. characteristic compensator and compensating the change with the temp. in a series resonance part. CONSTITUTION:A self-oscillation system is formed of an inductor 17, a series resonance part consisting essentially of an equiv. capacity component of an atomizer, and an amplifier 18, and a capacitor 20 as a temp. compensator compensates the change with the temp. in the series resonance part. Then the oscillation frequency in the oscillation driving part is changed in follow up to the deviation in the temp. of the mechanical resonance point operating efficiently as an atomizer.

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 configurations 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. In particular, as the ambient temperature changes, the mechanical resonance point at which the piezoelectric element vibrates efficiently also changes, so a method has been adopted in which the oscillation frequency is changed to follow the fluctuation of the resonance point.

For example, as seen in Japanese Patent Publication No. 50-13657 ``Ceramink Body Driving System'', the center frequency of the phase shifter is shifted to follow the resonance frequency deviation due to changes in ambient temperature.
There have been methods such as changing the oscillation frequency of an oscillator using a signal from a phase difference detector to eliminate the phase difference between the voltage and current, or to make the voltage and current to the piezoelectric element have the same phase.

However, the conventional atomizing device having an ambient temperature compensation function has to have an oscillator for generating a piezoelectric element drive signal, a phase detector, etc., and has to have a complicated structure as a whole.

Purpose of the Invention In order to eliminate such conventional drawbacks, the present invention is a simple oscillation drive unit constructed by focusing on the fact that an atomizer has capacitance characteristics, and also has an ambient temperature compensation function. The purpose is to provide an atomization device.

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 supply section facing the pressurized chamber. An atomizer is constituted by a nozzle section having a nozzle provided therein, and an electric vibrator that energizes the nozzle section and vibrates the nozzle, and current detection detects the current flowing through the atomizer. An oscillation drive unit is constituted by an amplifier, an amplifier that amplifies the signal of the current detector, and an inductor that transmits the signal from the amplifier to the atomizer, and the equivalent capacitance of the atomizer changes with respect to temperature. and a compensator for making the oscillation frequency of the oscillation drive unit follow the change in the mechanical resonance point of the atomizer by compensating for the change in the inductor and the atomizer, the oscillation drive unit, and the compensator. This constitutes the entire atomization device.

With this configuration, the series resonant section mainly consisting of the equivalent capacitance of the inductor and the atomizer, and the amplifier section form a self-oscillation system, and the temperature characteristic compensator compensates for changes due to temperature in the series resonant section. Then, the oscillation frequency of the oscillation drive unit is changed in accordance with the temperature shift of the mechanical resonance point that efficiently operates as a µ-enricher.

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

The liquid enters the pressurizing chamber 1 through the supply pipe 5, and during the atomization operation, the vibro for gas discharge is filled halfway. 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 hole for ejecting droplets is formed in the center of the nozzle portion 7 . Furthermore, an annular electric vibrator, here a piezoelectric element 9, is attached to the nozzle portion 7. This piezoelectric element 9 is a piezoelectric ceramic polarized in the thickness direction, and has electrodes on the surface to be joined to the nozzle and on the opposite surface.

1o is a lead wire for transmitting a 1 drive signal to the piezoelectric element 9, one of which is soldered to one electrode surface of the piezoelectric element 9, and the other is connected to the body 2 with a helix 11. When the mechanical vibration of the piezoelectric element 9 is excited by the drive signal, the nozzle part 7 is also energized and vibrates, so that the liquid in the pressurizing chamber 1 is discharged as atomized particles 12 as a result.

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

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

FIG. 2 is an electrical equivalent circuit that approximates the piezoelectric element 9, and is composed of 13 equivalent parallel capacitances C8 and a series inductance LO of 14°15.16, 1 capacitance CO, 1 resistance RO.

FIG. 3 shows the current change when a driving signal (for example, a sine wave) is applied to the piezoelectric element 9 of the atomizer by changing the frequency, and shows the current change when the pressurizing chamber 1 is filled with liquid. It shows the characteristics when loaded and the empty state with no liquid, that is, the characteristics when there is no load. In the no-load characteristics shown by the solid line, series resonance between LO14 and C015 shown in FIG. 2 occurs at an electrical resonance frequency of 11, and the peak value of one drive current appears. Also, the electrical anti-resonance frequency f
In No. 2, parallel resonance occurs between L014 and C813 shown in FIG. 2, and the drive current becomes a minimum value. The fr shown in the figure is approximately an intermediate frequency between fl and f2 and is called a mechanical resonance frequency. The broken line in Fig. 3 is the one under load, and the above-mentioned f1
．． The difference between the respective current values of f2 is not extremely large compared to when there is no load.

FIG. 4 shows changes in current value and changes in atomization amount with respect to changes in drive frequency under load. The amount of atomization is at its maximum value at the mechanical resonance frequency fx. When actually spraying, it is operated at a driving frequency near this fr.

FIG. 5 is a block diagram of an inductor-coupled self-oscillation system that transmits a signal from the amplifier section 18 to the atomizer (the piezoelectric element 9 as a vibration source) via the inductor 17. 19 is
This is a current detector that detects the current flowing through the atomizer. From Figure 3 above, 1. It can be seen that the drive current increases as the drive frequency f increases, and the atomizer exhibits capacity characteristics. If this equivalent capacitance is expressed as CT and the inductor 17 is L, then the oscillation frequency fO of the oscillation drive section shown in FIG.
It is determined by O-1/2πF■. In this basic configuration, by appropriately adjusting the value of the inductor 17, it is possible to drive the atomizer to oscillate at its mechanical resonance point. This configuration does not require an external oscillator.

A in FIG. 6 shows the change characteristics of the equivalent capacitance CT (pF) with respect to changes in the ambient temperature Ta ('C), which increases as the temperature rises. B in Figure 6 shows the change in the mechanical resonance point fr of the atomizer (solid line) with respect to the change in temperature Ta ("C), and the change in the oscillation frequency in the self-oscillation circuit system shown in Figure 6 (one point). Even if the inductance L is adjusted at T a = 20°C to match the oscillation frequency to the mechanical resonance point (for example, f = 50 (kt(z))), the temperature change in the inductance L and Depending on the value of the temperature change of the equivalent capacitance CT shown in Fig. 6A, it may not follow the temperature characteristics of the mechanical resonance point. This is a case where the oscillation frequency becomes less than the mechanical resonance point at high temperatures due to too much.

At this time, the efficiency of converting the electrical energy of the piezoelectric element into mechanical energy is low, and the amount of atomization also decreases as shown in FIG.

The present invention will be described below, in which a compensator is used to track a mechanical resonance point in a mountain oscillation system that treats the capacitance characteristics of an atomizer as an oscillation element.

FIG. 7 is a block diagram showing one embodiment of the present invention.
Components with the same numbers as those in the drawings have the same functions. A and B are capacitors 20 and 20, respectively, as compensators.
21 is connected in parallel and series with the atomizer, and the change due to temperature compensates for the change in CT shown in Figure 6A, changing the resonance characteristics with the inductor to the temperature characteristics at the mechanical resonance point. It matches. The oscillation frequency at A is capacitor 2
If ゜ is set to -01, f-1/2π is determined by F-1/2π. In order to compensate for the characteristics indicated by the dashed-dotted line in Figure 6B, (CT+C*) is required for the temperature change rate of CT.
It is sufficient to select a capacitor C1 that reduces the rate of temperature change at . The oscillation frequency in FIG. 7B is determined as follows, assuming that the capacitor 21 is 02.

f=1/2π door stone 5 In this case as well, it is sufficient to select 02 in which the composite characteristic of CT7)°C2 decreases the temperature change rate of only CT. In this way, using a capacitor connected in parallel or in series as a compensator is effective when the temperature change in the equivalent capacitance CT of the atomizer itself is large and the temperature change in the coil, etc. as an inductor is small and cannot be compensated for. It is a method.

FIG. 8 is a specific circuit diagram showing one embodiment of the present invention. The configuration of the compensator is such that a capacitor 2o is connected in parallel with a piezoelectric element 9 of the atomizer. The amplifying section 18 includes a transistor (
22, 23, 24, 26).

Resistance (26, 27, 28, 2!9, 30, 31.32)
, and capacitors (33, 34), and the current detector 19 is composed of a resistor 35. 36 is a DC power supply. The signal from current detector 19 is connected to capacitor 34
It is sent to the complementary 8EPP type amplifier through the inductor 17 to the piezoelectric element 9 and the compensator 20.
transmitted to.

Effects of the Invention According to the atomizing device of the present invention, in addition to the compact structure of the atomizing device itself, the configuration of the oscillation drive section is simple, and the compensator allows the atomizing device to operate efficiently. Resonance point tracking can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is an equivalent circuit diagram of a piezoelectric element, Fig. 3 is a current characteristic diagram for one drive frequency, and Fig. 4 is a current and atomization amount for each drive frequency. Figure 5 is a block diagram of the inductor-coupled self-oscillation system, Figure 6A is the temperature characteristic of the atomizer equivalent capacity, and B is the temperature of the mechanical resonance point and the oscillation frequency in the self-oscillation system. FIGS. 7A and 7B are block diagrams showing an embodiment of the present invention, and FIG. 8 is a specific circuit diagram of the present invention. 1... Pressure chamber, 2... Body, 5...
...Supply section, 7...Nozzle section, 9...
...Piezoelectric element, 17...Inductor, 18.
...Amplification section, 19...Current detector, 20
．． 21...Capacitor as a compensator. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Fig. 1 θ Fig. 2 HI31 Otsu \ \ / Fig. 3 S r = f Nohi motion I bow liquid 1 ri; Fig. 5 1 δ Fig. 6 o 50 T, ('c) 0
2050 Bowl

Claims (1)

[Claims] (1) A body equipped with a pressurized chamber filled with liquid. a supply unit for supplying liquid to the pressurizing chamber; a nozzle unit having a nozzle facing the pressurizing chamber; and an electric vibrator that biases the nozzle unit and vibrates the nozzle. an atomizer comprising: a current detector that detects the current flowing through the atomizer; an amplifying section that amplifies the signal of the current detector; and a signal from the amplifying section that transmits the signal to the atomizer. an oscillation drive unit comprising an inductor; and an oscillation drive unit that compensates for changes in the equivalent capacitance of the atomizer and changes in the inductor with respect to temperature, and adjusts the oscillation frequency of the oscillation drive unit to mechanical resonance changes of the atomizer. An atomization device consisting of a compensator for tracking. (4) The atomization device according to claim 1, wherein the compensator is constituted by a capacitor connected in parallel or in series with the atomization device.