JPS59201985A - Power source for liquid fuel pump - Google Patents

Abstract

PURPOSE:To maintain constant delivery by setting the referential voltage lower than the minimum fluctuation of AC input current and outputting the referential voltage when the input voltage is higher than the referential voltage thereby feeding constant AC voltage to an unimolf vibration chip. CONSTITUTION:A referential voltage setting circuit 11 includes diodes D3, D3', D4, D4' and referential voltage setting Zener diode ZD where Zener voltage Vz is set lower than the minimum level Vio of AC input voltage Vi. In an output circuit 12, transistors TR1 and Tr1' are turned on, off respectively by the initial half wave of the potential at point P to flow current through Tr1-D2-R5-D1'. Tr1 and Tr1' are turned off, on respectively by the next half wave of the potential at the point P to flow current through Tr1'-D2'-R5-D1'. Since the referential voltage Vzo is set below the minimum level, the potential at the point P will never fluctuate even if the input voltage Vi has fluctuated thereby the voltage across R5 will never fluctuate.

Description

[Detailed Description of the Invention] Technical Field> The present invention relates to a power supply device for a liquid fuel pump, and more specifically, the present invention relates to a power supply device for a liquid fuel pump, and more specifically, it is capable of driving a unimorph oscillator at a constant voltage without being affected by fluctuations in input AC voltage, and is capable of controlling the discharge flow rate. The present invention relates to a power supply device for a liquid fuel pump that can maintain a constant value.

<Prior art> Conventionally, electric motors and solenoids have been used as liquid fuel pumps for kerosene heating equipment, etc., and operate impellers, pistons, or plungers, and their rotational or reciprocating motion applies centrifugal force to the liquid fuel and discharges it. Or, it was discharged by expanding and contracting the internal volume of the cylinder. However, when a combination of an electric motor and an impeller or a piston, or a combination of a solenoid and a plunger is used, the transmission mechanism is complicated, so the pump itself becomes a blow type, and the internal structure becomes complicated.

In recent years, in order to improve the above-mentioned drawbacks of liquid fuel pumps, a liquid fuel pump has been proposed that has a simplified structure by using a unimorph vibrator that directly converts electrical energy into vibration in the pump mechanism. It became so. Generally, to make a unimorph oscillator vibrate, it is necessary to apply an alternating current voltage directly to the oscillator, and in the case of 1 or 2, the amplitude of the unimorph oscillator is proportional to the voltage value. Therefore, the following problems have arisen. (The commercial power supply is about 10 yen.
0V, but if you look at this in detail, it includes an error of about ±10%, in other words, it fluctuates between 90V and 110V. When this fluctuating voltage is directly applied to the unimorph vibrator, the amplitude changes according to the voltage fluctuation, and the liquid fuel discharged by the pump is affected by the amplitude, so the discharge flow rate cannot be maintained constant. It has been shown in close-up.

<Object of the invention> The object of the invention is to
An object of the present invention is to provide a power supply device for a liquid fuel pump that can supply a constant AC voltage to a unimorph vibrator.

<Configuration of the Invention> In order to achieve the above object, the power supply device for a liquid fuel pump according to the present invention provides a power supply device for a liquid fuel pump according to the present invention. a reference voltage setting circuit that sets a voltage value smaller than the minimum value of the fluctuating voltage as a reference voltage; and an output circuit that outputs a reference voltage value when the AC voltage input from the input circuit is greater than the reference voltage. It is characterized in that the unimorph resonator is vibrated by the output AC voltage of the output circuit.

<Example> Hereinafter, an example of a power supply device for a liquid fuel pump according to the present invention will be described in detail with reference to the drawings.

FIGS. 1A, 1B, and 1C show a partially cutaway plan view, a sectional view, and a partially cutaway bottom view of a liquid fuel pump using a unimorph vibrator as a vibrating part. Reference numeral 1 denotes a unimorph resonator, which is composed of a piezo element 2 and a thin metal plate 5 bonded together. 3 is the pump body, this body 3
The disk-shaped unimorph resonator 1 is configured to expand or contract the volume of the liquid pressurizing section 4, which is a space formed inside the unimorph resonator 1.
is located. 6 is a check valve on the discharge side, 7 is a check valve on the suction side, 8 is a discharge +11111111 hand, 9 is a lead wire for driving the unimorph vibrator 1, 10 is a ring 11 for fixing the unimorph vibrator on the suction side It is a joint.

In the fuel pump having the above structure, the unimorph vibration r1
When an alternating current voltage of a constant frequency is applied to the conductive wire connected to the . As can be seen from Figure 1 (B), the unimorph oscillator 1
Two check valves 6゜7 are arranged above, and when the shape changes to a concave shape, the discharge side check valve 6 is closed, and the suction side check valve 7 is opened, and the suction side joint-I-11 is closed. A predetermined amount of liquid fuel is sucked into the liquid pressurizing section 4 from the liquid fuel. Next, when it is deformed into a convex shape, the suction side check valve 7 closes and the discharge side check valve 6 opens, and the )1ν fuel in the liquid pressurizing section 4 is pumped through the discharge side joint 8 to the required part. Ru.

The unimorph resonator 1 is deformed into an uneven shape by application of an alternating current voltage, and as shown in FIG. 2(C), the amplitude ΔQ, which is the amount of deformation, is proportional to the magnitude of the voltage. therefore,
The discharge flow rate can be controlled by voltage. at the same time,
In order to maintain a constant discharge flow rate, the magnitude of the AC applied voltage must be kept constant. FIG. 3 shows an embodiment of the power supply device according to the present invention. The power supply device is an input circuit 10. Reference voltage setting circuit 11 and output circuit 12-3
Input terminals 10a, 10b of input circuit 10
An alternating current input power source AC is connected to. Of course, the input circuit may be configured to include this alternating current power source AC. The reference voltage setting circuit 11 includes diodes D3. D3', D4. D4', Zener diode ZD for reference voltage setting, dropper resistor R1, variable resistor VR and fixed resistor R for voltage adjustment
It is composed of 2. The Zener voltage Vz of the Zener diode ZD needs to be set smaller than the minimum voltage ViO of the input AC voltage 1. Generally, AC input power supply A
Even if the rated voltage of C is Vi, there is actually a fluctuation of ±10%, so if the input terminal is 0.9 V i ~ 1. l
We have to think of it as Vi. Therefore, the minimum voltage ViO in this case is 0.9Vi, and the Zener voltage (Z) needs to be set smaller than this 0.9Vi. In this case, the reference voltage VzO becomes VZ. The variable resistor VR is based on
This is used when it is desired to set the inner voltage smaller than z. As shown in the figure, if the human AC voltage Vi is iE and is a sinusoidal voltage, the potential at point 1) is the reference voltage value ■zO
The waveform will be clipped.

The output circuit 12 includes bypass diodes DI and D1', a reverse breakdown voltage prevention quartz l)2.1')2', and an impedance control transistor Tr1. 'T'r]
', He-Sumi flow control v resistor RI+, R4' and negative a;j resistor R5. In the first half-wave of the potential at point P, transistor i' r l is on, and transistor i' r I' is off, so that the current is 1''
r 1-→D 2- Fi! 5- flows as D1'. At the next half-wave of the potential at point P, the l-run transistor 'l''r1 is turned off, the transistor T r1 ' is turned on, and the current flows as 'T'r I '-'D2' = R5-DI'. , the voltage drop due to the diode is small, so the voltage applied to the load resistor R5 is approximately at point l)
The waveform is the same as the potential, but the difference is that it returns to the original alternating current (ij
3. Even if the input voltage V1 fluctuates, the reference voltage vzQ is set below its minimum value in consideration of its fluctuation range, so the potential at point P will not fluctuate, and as a result, the voltage across resistor R5 will not fluctuate. . The unimorph resonator 1 is connected in parallel with the resistor R5, and vibrates with a constant amplitude due to the output AC voltage 0 having the maximum amplitude VzO. Therefore, the discharge flow rate of liquid fuel is kept constant without being affected by fluctuations in input voltage.

FIGS. 4(A) and 4(B') show enlarged views of the waveforms of the input AC voltage and the output AC voltage.

It should be noted that the present invention is not limited to the above embodiments, but includes various design changes and modifications without departing from the technical idea of the present invention.

<Effects of the Invention> As described below, this invention
Since the reference voltage is set below the minimum &C of the fluctuating input terminal by the voltage 3V circuit, the constant AC output type I
By driving the -1-nimorph oscillator with this output voltage, the discharge flow rate of liquid fuel can be kept constant without being affected by fluctuations in the input terminal.
Il can.

[Brief explanation of the drawing]

Figures 1 (A), (B), and (C) are a partly cutaway plan view, a cross-sectional view, a partly cutaway bottom view, and Figure 2 (A )～(C)
is an explanatory diagram of the operation of the unimorph resonator, FIG. 3 is a circuit diagram of the power supply device, and FIGS. 4 (A) and (B) are input and output AC waveforms I in I. ■-Unimorph resonator, 10-input circuit, 11-reference voltage setting circuit, 12-output circuit, ■1 Human AC voltage, ■
〇-Output output current voltage, (1--- groups! (f' Lightning voltage Applicant Sharp Corporation agent Patent attorney Hisahiro Komori

Claims (1)

[Claims] (11) a reference voltage setting circuit 11 that sets a voltage value smaller than the minimum value of the fluctuating voltage as the reference voltage VzO when the AC voltage Vi applied directly to the vibrating part that pressurizes the liquid fuel fluctuates; The input circuit 10 is provided with an output circuit 12 that outputs a reference voltage value when the input AC voltage is larger than the reference voltage VzO, and the output AC voltage 0 of the output circuit 12 causes the conimorph oscillator 1 to
A liquid fuel pump power supply device that vibrates.