KR101212834B1 - Integrated fuel sender - Google Patents

Abstract

The present invention relates to an integrated fuel sender, in particular, to improve the problems of the conventional fuel-type fuel capacitive and capacitive sensing device to be electronic using the electrostatic capacitive integrated fuel incorporating the fuel sensing part and the fuel intake / recovery part It's about senders.
The present invention has been made in the background as described above, the control unit detects the capacitance changes in accordance with the flow rate flowing into the aluminum tube mounted inside the fuel tank of the vehicle every 0.25 seconds and the DC voltage (0.80 ~ 4.1 according to the change rate) The purpose is to provide an integrated fuel sender that allows the driver to accurately check the fuel level through the fuel gauge by outputting V) to a meter cluster.
In order to achieve the above object, the integrated fuel sender of the present invention is connected to the IC housing connector for transmitting power and signals; A body fixed to the fuel tank, including a module and a fitting; A sensor for detecting a difference in capacitance of a fuel, comprising: a ground (GND) cap sensor and an anode cap sensor composed of two aluminum pipes at regular intervals; A suction tube and a return tube constituting a path when transferring / recovering fuel to the engine; And it is characterized in that it comprises a mesh (MESH) is a mesh-shaped structure made so that foreign matter does not flow into the fuel supplied to the engine through the suction tube.

Description

Integrated Fuel Sender}

The present invention relates to an integrated fuel sender, in particular, to improve the problems of the conventional fuel-type fuel capacitive and capacitive sensing device to be electronic using the electrostatic capacitive integrated fuel incorporating the fuel sensing part and the fuel intake / recovery part It's about senders.

The flow meter of a conventional fuel tank for automobiles has a float installed in the fuel tank to move according to the height of the fuel, thereby changing the lever operating displacement to a resistance change, thereby causing the fuel gauge to appear in the fuel gauge, which is installed near the tip of the float arm. It is a structure that detects liquid level by using resistance change caused by contact movement between arc contactor and variable resistance plate. This conventional float flow meter is not only the case that the lever and gears get dirty, but also the structure is complicated, especially the small flow rate can not accurately measure the inventory of the desired flow rate because the consumer can not accurately measure There was a fault.

In addition, in order to eliminate the defect, the П with the permanent magnet piece 2 attached to the lower surface as shown in FIG. The lower end of the pressure sensing coil spring 3a is fixed to the hanging plate 4, and one end 5a of the steel fine wire 5 is fixed at the center thereof, and the other end of the steel fine wire 5 is the measurement needle (6). There is a known flow meter having a configuration that is fixed to). Such a water flow meter measures the head pressure of the fuel in the vehicle fuel tank 9 when the water pressure of the fuel in the vehicle fuel tank 9 is exerted on the sealed lower portion 3 of the frame 1 attached to the bottom surface of the vehicle fuel tank 9. (3) Since the pressure sensing coil spring 3a in the longitudinal direction is stretched and contracted, the steel fine wire 3 connected to the tip hanging plate 4 is moved while the tip hanging plate 4 of the bridle 3 is raised and lowered. 6) is to measure the flow rate in the tank.

On the other hand, the capacitive liquid level inspection device is focused on the fact that the material has a higher dielectric constant than the vacuum, the dielectric constant is one of the basic electrical constants of the insulating material and the material exhibits the property of preserving electrical energy. Therefore, if a dielectric is inserted between two conductors, more electric charge is required to make a constant potential, and the capacitance between two conductors increases, so that the capacitance increases or decreases according to the increase or decrease of liquid level. It is possible to detect the face value using this.

Float type liquid level detection device has poor contact between contactor and variable resistance plate, malfunction due to abrasion of variable resistance plate, error due to bending of float arm, each part between E (empty) level and 1/2 level section. There are disadvantages such as uneven fuel level indication of fuel gauge indicator due to large change of resistance of segment, inclined state in vehicle or inaccurate level detection during liquid level vibration and NTC for fuel supplement warning function. (Negative Temperature Coefficient) There is a problem of installing thermistor separately. In addition, the flow meter was difficult to measure accurately and there was a problem frequently.

Even in the case of the capacitive liquid level detection device, the disadvantage of the inaccurate level detection of the inspected state or the liquid level vibration was difficult to solve.

The present invention has been made in the background as described above, the control unit detects the capacitance changes in accordance with the flow rate flowing into the aluminum tube mounted inside the fuel tank of the vehicle every 0.25 seconds, according to the change rate of the DC voltage (0.80 ~ 4.1 The purpose is to provide an integrated fuel sender that allows the driver to accurately check the fuel level through the fuel gauge by outputting V) to a meter cluster.

It is another object of the present invention to provide an integrated fuel sensor which configures a path so that fuel in a fuel tank can be transferred to an engine and guides the fuel recovered after use to the fuel tank.

Still another object of the present invention is to provide an integrated narrow fuel sender having a function of discharging to the outside when internal pressure is generated in the fuel tank.

In order to achieve the above object, the integrated fuel sender of the present invention is connected to the IC housing connector for transmitting power and signals; A body fixed to the fuel tank, including a module and a fitting; A sensor for detecting a difference in capacitance of a fuel, comprising: a ground (GND) cap sensor and an anode cap sensor composed of two aluminum pipes at regular intervals; A suction tube and a return tube constituting a path when transferring / recovering fuel to the engine; And it is characterized in that it comprises a mesh (MESH) is a mesh-shaped structure made so that foreign matter does not flow into the fuel supplied to the engine through the suction tube.

According to the present invention, all IN / OUT ports protruding out of the fuel tank can be integrated and semi-permanent quality in a non-contact manner utilizing the capacitance of the fuel as compared to the contact sender, which may cause malfunction due to contact wear. Guaranteed effect is possible. In addition, the shape of the fuel tank is simpler than that of the contact type sender, so that the internal shape of the fuel tank is simplified, and the voltage transmission method, not the resistance transmission method, enables more accurate signal transmission and reception to environmental factors. It is possible to obtain an effect that can eliminate the occurrence of quality problems such as malfunctions.

1 is a cross-sectional view of a state of use of a conventional air flow meter.
2A and 2B are cross-sectional and perspective views of the integrated fuel sender of the present invention.
3 is an enlarged cross-sectional view of the AA portion of FIG. 2A of the present invention.
4 shows the sensing part of the control unit in the body part of the integrated fuel sender of the invention.
FIG. 5 shows the voltage waveforms of the reference oscillator of FIG. 4.
FIG. 6 shows the voltage waveform of the reference oscillator through the integrator of FIG. 4.
FIG. 7 illustrates a power supply of the microcomputer in the body of FIG. 2A.
8 illustrates a control unit of the microcomputer.
FIG. 9 illustrates a low pass filter circuit in the body portion of FIG. 2A.
10 is a view showing a state in which light oil and water are contained in the fuel tank.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2A and 2B are cross-sectional and perspective views of the integrated fuel sender of the present invention.

As shown in FIG. 2A, the integrated fuel sender of the present invention includes a connector 10, a body 20, a ground (GND) cap sensor 30, an anode cap sensor 40, a suction tube 50, and a return tube ( 60) and a mesh 70.

The connector 10 is a portion that is connected to an IC (Tyco-AMP 282088-1) housing to transfer power and signals. The body 20 is a part which is fixed to the fuel tank including the module and the fitting part. Ground cap sensor 30 and the anode cap sensor 40 is a sensor for detecting the difference in the capacitance of the fuel is composed of two aluminum pipes at regular intervals. The intake tube and return tube 50, 60 form part of the path when fuel is transported / recovered to the engine. The mesh (MESH) 70 is a mesh-shaped structure made to prevent foreign substances from entering the fuel supplied to the engine through the suction tube 50.

3 is an enlarged cross-sectional view of a portion A-A of FIG. 2A of the present invention. The outside pipe 30 shown in FIG. 3 is the ground cap sensor 30 shown in FIG. 2A, and when fuel flows between the outside pipe 30 and the inside pipe 40 (anode cap sensor), As shown, the outside pipe plays the ground (GND) and the inside pipe plays the positive role (+) so that the dielectric constant changes according to the flow rate, and the sensing portion of the control unit (hereinafter referred to as CAV424) of the control unit in the body It receives the input and outputs a DC voltage that meets the condition of the meter cluster.

4 shows the sensing part of the control unit in the body part of the integrated fuel sender of the invention.

The sensing unit uses the CAV 424. The CAV 424 is a capacitance / voltage converter that reads capacitance values and converts them into a constant voltage. C _x1 110a is a comparative reference capacitor of C _x2 110b. C _x2 is a variable capacitor whose capacitance varies with flow rate. C _osc 120 is a capacitor used to drive the reference oscillator, where C _osc = 1.6 × Cx1. The reference oscillator 130 is a reference oscillator using a crystal as an oscillation source. Integrators 1 and 2 140 are integrators that integrate the capacitances from C _x1 110a and Cx2 110b. A square wave output from the integrator 140 is compared by the comparator 164 in the signal control unit 160 is composed of a resistor (161), OP amplifier 162 and the C _L1 (163) by a C _L1 (163) The cutoff frequency Fc of the first low pass filter is determined. The C _L2 163 also determines the cutoff frequency of the second order low pass filter, which consists of the resistor 165, the OP amplifier 166, and the C _L2 163. RL1 and RL2 167 are resistors for determining the amplification ratio of the second order low pass filter.

R _CX 151 is a resistor that adjusts the final output voltage of CAV 424. The voltage adjusting range of R _CX1 151 and R _CX2 151 varies according to the capacitance measurement range. That is, fine adjustment is possible. The square wave from the integrator 140 is converted into a DC voltage by the signal adjusting unit 160. Other configurations not specifically related to the present invention will not be described.

5 shows the voltage waveform of the reference oscillator. V _{OSC HIGH} is high oscillation voltage, V _{OSC LOW} is the low oscillation voltage.

When the voltage waveform is input from the front end of the capacitor to be measured and passes through the integrators 1 and 2 (140) at the rear end, the voltage waveform is output as a waveform as shown in FIG. The frequency calculation is as follows. F _OSC = 2.5 V / (2 × ΔV _OSC × C _OSC × R _OSC ) where F _OSC is the frequency of the reference oscillator, and V _OSC is the magnitude of the amplitude of the frequency of the internal reference oscillator of the CAV 424, ie V _{OSC HIGH} -V _{OSC LOW} It is the default value inside CAV 424 when operating voltage is applied (5V). R _OSC determines the current of the reference oscillator with the external resistance of the reference oscillator. The amplitude of the output waveform is determined by the size of the reference capacitor C _x1 and the measurement capacitor C _x2 .

The formula for calculating the output waveform maximum voltage is as follows. V _CX = 2.5 V / (2 × F _OSC ) × {1 / (C _X1 × R _CX1 ) -1 / (C _X2 × R _CX2 )}

The triangular waveform passed through the integrator 140 passes through a second low pass filter and outputs a DC voltage of 1V to 4V according to the change of the measurement capacitor.

Here, the cutoff frequency calculation of the low pass filter is as follows.

Fc = 1 / (2π × CL), which is 1/500 times the vibration frequency or less.

The CAV 424 (100) reads the capacitance and outputs a constant current according to the rate of change. However, because the measuring range is 0.5pF to 2000pF, it does not match the capacitance of the integrated fuel sender, which varies from 100pF to 350pF, so the changing voltage width does not match the voltage width required by the cluster.

The microcontroller shown in FIG. 7 and FIG. 8 (hereinafter referred to as "microcom") converts the voltage input from the CAV 424 (100) into a digital signal, which is again converted into a complete direct current through a quadruple low pass filter. Will change into voltage.

7 illustrates a power supply unit of the microcomputer. The power supply unit receives a 28V DC voltage and converts it to 5V.

In the power supply unit 700 shown in FIG. 7, the ZD1 701 is a Zener diode, and the D2 702 is reversed as shown, and both are protection elements that protect the power supply terminal when a reverse voltage is introduced. The D1 703 is a device that protects the ZD1 701 and the D2 702 due to overcurrent when the reverse voltage is introduced. The TVS1 703 and the ZD1 701 are elements that protect the power supply terminal when an overvoltage is introduced. R10 704 is a resistor that limits the current flowing into the voltage regulator 706 at a later stage. U3 706 functions as a voltage regulator and is also operable at a low voltage of a 24V power supply. L1 707 and CE1 708 block the noise flowing into the power source. Other components not described are those for power stabilization.

8 shows a control unit of a microcomputer.

As described above, the microcomputer circuit 800 converts the voltage input from the CAV 424 100 into a digital voltage (DC voltage). R11 (801) and C13 (802) are reset delay circuits that prevent the circuit from operating until the clock is stabilized upon micom reset. That is, C13 802 is a smoothing capacitor. In addition, L2 803 and TC1 804 are filters for preventing noise from flowing into the power supplied to the microcomputer internal A / D converter.

In the CAV 424 which is a sensing unit of the control unit illustrated in FIG. 4, a microcomputer as shown in FIG. 8 is used to adjust an output voltage width according to a change in measurement capacitance according to a user application. However, since the microcomputer 800 outputs only a digital signal (square wave), the microcomputer 800 cannot directly apply the output to the cluster input. Therefore, a filter circuit as shown in FIG. 9 is used. This filter circuit is also incorporated in the body portion of FIG. 2A.

In the circuit shown in Fig. 9, the filter 900 composed of R and C converts a square wave from the microcomputer 800 into a DC voltage as a passive filter, and the OP amplifier 901 in the rear stage serves as a buffer. DC voltage which completely removes noise components through the RC active filter 902 and the OP amplifier 903, which filters out noise components that have not been removed from the filter 900 in front of the circuit, and also serves as a smoothing circuit. Can be output to the cluster.

The following table shows the output voltage values for each fuel level.

        level           Voltage (V)              tolerance         pool          4.00

± 0.10

        3/4          3.25         2/4          2.65         1/4          1.75        Empty (EMPTY)          0.90

     In the present invention, when the dielectric constant of air is 1 to prevent capacitance malfunction, the dielectric constant of diesel fuel is 2.88, the dielectric constant of water is 65, and the dielectric constant of diesel fuel is relatively lower than that of other materials. When the capacitance surges due to water or other liquids having a higher dielectric constant than diesel, the driver outputs an empty signal. That is, when a predetermined capacitance (500pF) or more is input, the microcomputer determines that it is an abnormal phenomenon and outputs an empty signal.

Water has a lower specific gravity than diesel and does not mix with each other. As shown in FIG. 10, the upper portion of the water is separated into diesel. Since water and diesel do not mix with each other, they do not produce water or other materials with different permittivity than diesel. In other words, the product does not judge the content of water contained in the diesel, but determines whether the water laid down touches the AL pipe of the product. The difference between the inside pipe of the product and the bottom of the tank is about 20mm and the difference between the suction hose is about 16mm. As a result, water is drawn from the suction tube before the inside pipe and water come into contact. In addition, even if the water is on the ground due to the shaking caused by the driving of the vehicle, the water will touch the inside pipe due to the shaking, thereby affecting the capacitance.

According to the present invention, all IN / OUT ports protruding out of the fuel tank can be integrated and semi-permanent quality in a non-contact manner utilizing the capacitance of the fuel as compared to the contact sender, which may cause malfunction due to contact wear. Guaranteed effect is possible. In addition, the shape of the fuel tank is simpler than that of the contact type sender, so that the internal shape of the fuel tank is simplified, and the voltage transmission method, not the resistance transmission method, enables more accurate signal transmission and reception to environmental factors. It is possible to obtain an effect that can eliminate the occurrence of quality problems such as malfunctions. In addition, the integrated fuel sender of the present invention is mounted on the fuel tank to deliver the fuel to the fuel injector, and consumes the remaining fuel back to the fuel tank.

The integrated fuel sender according to an embodiment of the present invention has been described above with reference to the accompanying drawings. However, the present invention is not limited thereto and various modifications may be made by those skilled in the art without departing from the spirit and scope of the appended claims. Changes and variations may be made, and such changes and variations will be construed as being within the scope of the present invention.

1: frame 2: permanent magnet
3: bellows-style bure 3a: pressure-sensing spring
4: hanging plate 5: steel wire
6: measuring needle 7: tube tube
8: bias spring 10: connector
20: Body 30: Ground (GND) Cap Sensor
40: anode cap sensor 50: suction tube
60: return tube 70: mesh
80: fuel 100: sensing unit

Claims (7)

A connector connected to the IC housing and transmitting power and signals;
A body fixed to the fuel tank, including a module and a fitting;
A sensor for detecting a difference in capacitance of a fuel, comprising: a ground (GND) cap sensor and an anode cap sensor composed of two aluminum pipes at regular intervals;
A suction tube and a return tube constituting a path when transferring / recovering fuel to the engine; And
Integrated fuel sender comprising a mesh (MESH) is a mesh-shaped structure made so that foreign matter does not flow into the fuel supplied to the engine through the suction tube. The method according to claim 1,
The pipe may be an outside pipe and an inside pipe, wherein the outside pipe serves as a ground (GND), and the inside pipe serves as an anode (+). The method according to claim 1,
The body is an integrated fuel sender comprising a microcontroller including a power supply and a control unit. The method according to claim 3,
And the power supply unit includes a protection circuit and a stabilization circuit. The method according to claim 3,
The control unit is an integrated fuel sender, characterized in that it comprises a voltage conversion circuit and a reset delay circuit. The method according to claim 3,
And the body comprises a filter circuit. The method of claim 6,
Wherein said filter circuit comprises an R, C filter and an OP amplifier.

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