JPS59203889A - Liquid fuel pump - Google Patents

Abstract

PURPOSE:To control the flow amount of fuel correctly and easily with a simple structure by a method wherein the mechanical vibration of a piezo vibrtor, which can directly be controlled electrically, is acted on the fuel directly to deliver the fuel. CONSTITUTION:When an AC voltage is impressed on lead wieres 11, the piezo vibrator 6 vibrates with a frequency equal to the same of the AC voltage. When the piezo vibrator 6 is bent, the volume of a pressurizing chamber 5 is enlarged and a non-return valve 9 is opened while the non-return valve 10 is closed and the fuel is sucked into the pressurizing chamber 5 from a pipe 3 for sucking through a inflow path 7. When the piezo vibrator 6 is returned to the original shape thereof, the volume of the pressurizing chamber 5 is decreased, the internal pressure thereof is increased and the non-return valve 9 is closed while the non-return valve 10 is opened and the fuel is delivered into a delivery pipe 4 from the pressurizing chamber 5 through an outflow path 8. By repeating above- described motions, the fuel is flowed. The delivery flow amount of fuel in the pump 1 may be controlled by controlling variably the electric source voltage between lead wires 11.

Description

TECHNICAL FIELD The present invention relates to a liquid fuel pump that pumps liquid fuel, and particularly to a liquid fuel pump that uses a piezoelectric vibrator in its mechanism.

Prior Art Conventional liquid fuel delivery pumps use electric motors, solenoids, etc. to rotate the pump blades and apply centrifugal force to the liquid fuel, thereby discharging the fuel by 1! A method is used in which fuel is discharged by reciprocating the piston or plunger within the cylinder and expanding or contracting the internal volume of the cylinder.

By the way, the impeller used in this kind of conventional pump,
Parts that directly act on fuel, such as pistons and plungers, cannot have their operation controlled directly by electrical signals. In other words, the impeller and piston are
The plunger is controlled by the power supply control of the electric motor to which the 11" rotation is transmitted through the 11+, and the plunger is controlled by the control of the solenoid current which generates a magnetic field in the solenoid.

For this reason, conventional fuel pumps of this kind have disadvantages in that they require an intermediate transmission mechanism such as a dual-unit system, which increases the size of the device itself and complicates its internal structure.

Purpose The purpose of the present invention is to eliminate the above-mentioned drawbacks of conventional liquid fuel pumps and discharge fuel by directly applying mechanical vibrations of a piezoelectric vibrator that can be directly controlled electrically to fuel. The object of the present invention is to provide a fuel pump which has a simple structure and can accurately and easily control the fuel flow rate.

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

In Figures 1 to 3, the pump body has an opening in the center where a pressurizing chamber for applying pressure to the fuel is formed, such as a disc-shaped upper layer 1a through which liquid fuel is sucked in and discharged from the outside. A lower layer IC having the same shape and a middle layer portion 1b having the same shape that allows fuel to flow between the upper layer 1a and the lower layer IC are connected to each portion 1a.
, 1bslc are combined into one body by fastening the screw 2 into a hole formed at the end of the two.

Reference numeral 3 denotes a suction pipe protruding from the upper surface of the upper part 1a, through which fuel is sucked into the pump body 1 from the outside through the suction pipe 3. In addition, in the same way, upper layer 1
3 and 5 are the discharge knobs provided in the lower part of the pump body 1, and 3 and 5 are the discharge knobs provided in the lower part of the pump body 1.
A fuel pressurizing chamber 1) and 7) is provided in the circular opening 1-1,
The fuel 1 is formed by being sandwiched between the piezoelectric resin 0 (details of which will be described later) and the surface of the middle layer 1b, and the fuel 1 is stored and pressurized.

7, the fuel is 1'l' from the suction pipe 3 in the IF chamber 5cm.
5-・It is an inflow channel, and it is 1, i, i, addition! ”−
This is an outflow path through which fuel flows out from the chamber 5 to the discharge pipe 4. The inflow passage 7 and the outflow passage 8 are formed so as to penetrate through the eye 2, the upper layer portion 1a, and the middle layer portion 1b.

9 is a check valve that prevents the fuel from flowing backward in the inlet passage 7; -, f". The reverse IE valves 9 and 10 are installed so as to cover the inflow passages 7 and 8, respectively, at the joint surface between the upper layer 1a and the middle layer 31 (1b).

The piezoelectric unimorph 6, not shown in FIG. 4, is formed by concentrically bonding a thin metal disk 6a and a disk-shaped piezoelectric element 61 with a smaller diameter than the thin metal disk 6a. Disk 6
A and the piezoelectric element 61] (d) are each connected with a conductive wire 11 for voltage application.

The piezoelectric unimorph 6 described above is fixed to a flange 12 formed at the lower part of the inner wall of the opening at the center of the lower layer IC.
Close the opening of C to prevent liquid leakage. Furthermore, a metal ring 13 having the same outer diameter as this opening is fitted onto the upper side of the piezoelectric unimorph 6 to create a gap between the piezoelectric unimorph 6 and the lower surface of the middle layer portion 1b so that the piezoelectric unimorph 6 can freely bend upward. That is, a pressurized chamber 5 is formed.

In the configuration described above, when an alternating current voltage is applied between the conducting wires 11, the piezoelectric unimorph 6 vibrates at a frequency equal to the alternating voltage, and as shown in FIGS. The shape changes as shown in (a).

As shown in FIG. 5 (1+), when the piezoelectric unimorph 6 bends, the volume of the pressurizing chamber 5 expands and its internal pressure decreases, the check valve 8 opens and the check valve 9 closes, and the suction pipe Fuel is drawn into the pressurizing chamber 5 from the pressurizing chamber 3 via the inflow path 7.

As piezoelectric unimorph 6 returns from FIG. 5(b) to FIG. 5(a), the volume of pressurizing chamber 5 decreases and the internal pressure increases, causing check valve 8 to close and check valve 9 to close. When opened, -C fuel 1 is discharged from the pressurizing chamber 5 to the discharge vibro through the outflow path 8.

” The operations described above are repeated periodically, and the combustion
, continuously flows through the pump body 1 at a constant flow rate.
! be done.

By the way, the amount of displacement of the piezoelectric unimorph 6 shown in FIG. The fuel discharge flow Ei: of the pump is proportional to the displacement amount and vibration frequency of the piezoelectric unimorph 6, and therefore proportional to the power supply voltage and its frequency. 7. Since a commercial power source with a frequency of 601-, Iz or (':J, 5011Z) is used, the vibration frequency of the unimorph 6 cannot be varied.

Therefore, in the present invention, the electric current between the conducting wires 11 is variably controlled to control the fuel discharge flow of the pump.

FIG. 6 shows an example of the electric circuit 14 for the power supply voltage control device 61.

Figure 6 ((Input terminals
A 1F electric unimorph 6 and a resistor R are connected in parallel between the output terminals Y and Y, and a control voltage oUT of the commercial power supply voltage VIN is applied to the piezoelectric unimorph 6.

Between input terminal X and output terminal Y, output voltage vooT
The collector and emitter of the control transistor Tr1 and the diode I)1 for preventing reverse 1ii-1 voltage are connected in series, and the bypass diode 1]2 is connected in parallel with the transistor TRIr and the diode D. connected to. Similarly, input terminal X' and output terminal Y
' between the transistor Tr1' and the diode I),
', I)2' are connected.

q- diode connected in series with i)3. , D3
' and diodes D4 connected in series with each other. 'f)
4' is connected in parallel between the input terminals x and x' to form a bridge circuit 2, which performs single-phase full-wave rectification of the power supply voltage VIN and outputs it to terminals a, b, and J:p.

Between the terminals a and b, Zener diodes ZD, Zl)' connected in series with each other and variable resistors VR and R2 connected in series with each other are connected through a voltage drop resistor I(3), respectively. , connected in parallel.

On the other hand, between both bases of the transistor "'l + ""'l'
, ' are connected to the -C11'1 column through the ends 1'-d, and are further connected to the terminals -] &: J1 and the transformer resistor IJ'1□VH.

In this way, the '1liIE output from terminals a and b
, IN are rectified by the Zener knee diode Z+1. Z
After being regulated by a circuit consisting of a resistor V R and a circuit 2, it is applied to the base of a transistor Tr through a terminal d.

'I"r, / switching control is performed,
The switch SW is connected in parallel with the Zener diode (Zl+). , In the above circuit configuration, during the half cycle when the voltage ~'H, I is I', the diode 1)4 is connected from the input terminal X.
, resistor and 3, V R11 (2, Zener diode [, Z
I], ZD and the diode JJ3', a current flows at the input terminal X'. As a result, the transistor TrI is connected from the terminal d through the resistor R4.
A positive voltage is applied to the base of the transistor ′I″r
1 is turned on, and a positive power supply voltage ■■N is applied to the load 16 via the transistor 1'r1 and the diode D1.

On the other hand, during a half cycle when the power supply voltage ■■N is negative, the input terminal X' is connected to the diode D4, the resistor ■, VfL, and R.
2. Through the circuit formed by the Zener diodes ZD, ZD' and the diode JJ1, a current flows at the input terminal X1, and in the same way as above, the transistor '
rr1' is turned on, and the negative power supply voltage ■■N is applied to the load 16.
is applied to

The waveform of the base voltage Vz applied to the terminal d after the above operation is repeated is shown in FIG. 7(a), and the voltage between the output terminals y and y' controlled by this waveform is
However, the waveform of the base voltage ■z shown in FIG. 7(b) is obtained by full-wave rectification of the sine wave of the power supply voltage ■IN in a bridge circuit, and then the Zener diode Z, 1. ),
Depending on ZD', the voltage ■ZH or p in Fig. 7(a)
'This is a substantially trapezoidal waveform clamped at VZL. If you open the switch SW, the Zener die (ZD, ZJ)
Voltage is applied to both ', the clamp voltage becomes VZH, and the switch SW is closed.
A voltage is applied only to D', and the clamp voltage becomes ■zTJ.

With the base voltage as above, the transistors '11r and Il
When controlling l, ,,' by switching, the output voltage ■0I
JT (rJ-1 power supply voltage ■■N is clamped at voltage VC' in FIG. 7(b)) UTH or t, 1, voUTL, resulting in a substantially trapezoidal waveform.

In Figure 7, voltages VZH and VOUTL1 and voltage Z
++ and VOUTL correspond to each other.

Then, as shown in Fig. 8, the output voltage H= Vou-
Since r is proportional to the fuel discharge flow rate Q of the pump, the output JJ
Tjlpressure ■OUT KavOUTL br Louis (i, ■
otrr+-+ VC clamped, i.e. switch S
When W is closed or opened by ←1, a voltage ■oUT having a substantially trapezoidal waveform is applied to the piezoelectric unimorph 6, and this voltage ~
'Since the unimorph deforms in proportion to OUT,
Fuel discharge flow: 11, (', IC, becomes QL or QH of the first IC. 1) In this way, in this embodiment, the Zener voltage of the Zener diodes ZD, Zl is set appropriately, and the switch is turned on. By opening and closing the SW, the discharge flow 1) can be switched into two stages of strength and weakness.

In addition, in the above-mentioned embodiment, a Zener diode 1 is further added.
・If you add ゛ and increase the number of switches connected in parallel with each Zener diode, it is possible to vary the discharge current meter in multiple stages.

Effects As described in detail above, according to the present invention, liquid fuel is pressurized by mechanical vibration of a piezoelectric vibrator, and a power supply voltage control device for driving the piezoelectric vibrator is provided to control the pressurized state of the fuel. Since the fuel discharge amount is adjusted by directly controlling electrically, it is possible to provide a liquid fuel pump that has a simple structure and can easily and accurately control the fractional flow rate.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is a top view showing the same embodiment, Fig. 3 is a bottom view showing the same embodiment, and Fig. 4 is a cross-sectional view showing the same embodiment. A front view showing the piezoelectric unimorph used; FIG. 5 is a side view showing the deformation of the piezoelectric unimorph;
FIG. 6 is a circuit diagram showing the power supply control device of the same embodiment, and FIG. 7 shows the waveform of the base voltage VZ applied to the transistor of the power supply control device and the waveform of the output voltage OUT of the device. , 71e diagram, FIG. 8 shows the output voltage V of the device.
This is a diagram showing the relationship between oUT and discharge flow by type: l:Q. ■Liquid fuel pump main body, 5 pressurizing chamber, 6-4L electric unimorph, 7 inlet channel, 8 outlet channel, 14 electric circuit for power supply voltage control device. Patent applicant Sharp Corporation

Claims (1)

[Claims] (1) A storage chamber that temporarily stores fuel, which is formed between the liquid fuel inflow path and outflow path leading to the outside of the pump body, and a storage chamber that forms part of the inner wall of this storage chamber and stores fuel by mechanical vibration. The piezoelectric vibrator is equipped with a piezoelectric vibrator that pressurizes fuel in the room and periodically discharges the fuel into the outflow passage, and a control device that controls the output type JE of the power supply device to apply voltage to the piezoelectric vibrator. A liquid fuel pump characterized in that the discharge flow rate of fuel is controlled by adjusting the amount of deformation of the liquid fuel pump.