Wing soft fuel tank air leakage detection circuit

Abstract

The utility model relates to the technical field of electronic circuits, in particular to an air leakage detection circuit for a wing soft oil tank, which comprises an acoustoelectric probe HTD, resistors R1 to R15, capacitors C1 to C16, transistors VT1 to VT3, slide rheostats KP and KD28 chips, a 9V power supply, a switch S and a light emitting diode D1. The device is used for detecting aircraft wing fuel tank sealing conditions. The tester detects weak air leakage sound when the soft oil tank is poor in sealing through the acoustoelectric probe and converts the weak air leakage sound into an electric signal, the signal is amplified, filtered and the like through a circuit, and finally the sealing condition is judged through the light intensity of the LED. The instrument has the advantages of being simple in circuit structure, good in circuit consistency, low in cost, suitable for multiple models and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, in particular to a wing soft oil tank air leakage detection circuit, in particular to a oil tank sealing detection circuit based on a KD28 chip. Background Art

[0002] Aircraft fuel tanks are cavity structures formed by sealing and assembling the aircraft's internal structure. They are typically composed of materials such as stainless steel, aluminum alloy, composite materials, and synthetic rubber. Soft fuel tanks made of synthetic rubber offer advantages such as oil resistance, corrosion resistance, and aging resistance. They also exhibit low leakage rates if ruptured by a projectile or high-speed maneuvers. Therefore, synthetic rubber fuel tanks are widely used in military aircraft.

[0003] Fuel tanks are typically placed within aircraft wings. During the aircraft design phase, due to the need to fully consider performance, weight, and form factors, the limited wing space is maximized to increase the tank volume and fuel capacity. However, after assembly, the limited space makes inspecting the fuel tank's seal difficult. Traditional air and oil leak testing methods suffer from long cycle times and difficulty in removing leaks. Therefore, it is essential to design an aircraft fuel tank seal test device to verify fuel tank leaks. Summary of the Invention

[0004] The purpose of the present invention is to provide an aircraft wing oil tank sealing detector relying on hardware circuit, which is used for checking the sealing condition of the aircraft wing soft oil tank.

[0005] The technical solution of the present invention is:

[0006] Provided is a wing soft oil tank air leakage detection circuit, comprising an acoustic and electrical probe HTD, resistors R1 to R15, capacitors C1 to C16, transistors VT1 to VT3, a sliding rheostat KP and a KD28 chip, a 9V power supply, a switch S and a light-emitting diode D1;

[0007] The pins of the KD28 chip are connected as follows: pin 4 is connected to the positive electrode of the battery, and pin 4 is connected to the negative electrode of the power supply through capacitor C12; pin 4 is connected to the source of VT1 through resistor R12, resistor R4, and resistor R2 in sequence;

[0008] The 5th pin is connected to the negative terminal of the battery through capacitor C13, resistor R15, light-emitting diode D1, and switch S in sequence; the 5th pin is connected to the negative terminal of light-emitting diode D1 through capacitor C13, capacitor C16, and resistor R13 in sequence;

[0009] Pin 3 is connected to the cathode of LED D1 through capacitor C14, capacitor C15, and resistor R13 in sequence; Pin 3 is connected to pin 8 through capacitor C14;

[0010] Pin 6 is connected to the cathode of light-emitting diode D1 through capacitor C10;

[0011] Pin 7 is connected to the negative pole of the power supply through capacitor C11;

[0012] Pin 1 is connected to the sliding output terminal of the sliding resistor KP through capacitor C9;

[0013] One end of the sliding rheostat KP is connected to the cathode of the light-emitting diode D1, and the other end is connected to the collector of VT3 via capacitor C7; one end of the capacitor C5, one end of the resistor R6 and one end of the resistor R9 are all connected between the resistor R4 and the resistor R12, the other end of the capacitor C5 is connected to the cathode of the power supply, the other end of the resistor R6 is connected to the collector of the transistor VT2, the other end of the resistor R9 is connected to the collector of the transistor VT3, and the collector of the transistor VT2 is connected to the collector of VT3 via C6; the emitter of the transistor VT3 is connected to the cathode of the light-emitting diode D1 via resistors R10 and R11 in sequence; the emitter of the transistor VT2 is connected to the cathode of the light-emitting diode D1 via resistor R7; the collector of the transistor VT2 is connected to the base of VT3;

[0014] A resistor R3 and a capacitor C4 are connected in parallel between the drain of transistor VT1 and the cathode of light-emitting diode D1; the source of transistor VT1 is connected to the base of VT2 via capacitor C3, the base of transistor VT2 is connected to the cathode of light-emitting diode D1 via R5, and the base of transistor VT2 is connected to the cathode of light-emitting diode D1 via resistor R8 and capacitor C8 in sequence;

[0015] One end of capacitor C2 is connected between resistor R4 and resistor R2, and the other end of capacitor C2 is connected to the negative pole of the power supply;

[0016] The positive electrode of the acoustic and electrical probe HTD is connected to the gate of the transistor VT1 through the capacitor C1, and the negative electrode of the acoustic and electrical probe HTD is connected to the negative electrode of the light-emitting diode D1; the gate of the transistor VT1 is connected to the negative electrode of the light-emitting diode D1 through the resistor R1.

[0017] Furthermore, the power source is a 9V battery.

[0018] Furthermore, transistor VT1 is a 3DJ6 type field effect transistor.

[0019] Furthermore, the acoustic-electric probe is a piezoelectric ceramic piece.

[0020] Furthermore, the transistor VT2 and the transistor VT3 are low-noise NPN silicon transistors 3DG6.

[0021] Furthermore, the acoustic and electrical probe collects signals through a universal tube.

[0022] Furthermore, the fuel tank sealing detection circuit based on the KD28 chip is an integrated circuit and is installed in a shell. The shell is connected to a universal tube, one end of which leads to the acoustic and electrical probe HTD, and the other end serves as a detection end extending into the fuel tank.

[0023] The KD28 chip includes two internal amplifier circuits that amplify electrical signals. The HTD acoustic sensor is an acoustic sensor that converts the frequency of collected sound signals into electrical signals. The HTD's electrical signal is filtered by C1 and R1 and coupled to the gate of VT1. VT1 is a 3DJ6 field-effect transistor. Acting as an impedance converter, with its high input impedance and low output impedance, it transmits the detected signal to the coupled amplifier composed of VT2 and VT3 for preamplification. The signal emitted from VT3's collector is then amplified in the dual-power amplifier integrated circuit KD28, where the first stage is used for low-frequency amplification and the second stage for power amplification, driving the alarm circuit's LEDs.

[0024] The acoustic and electrical probe collects signals through a universal tube. The tube is made of an inner carbon steel tube and an outer polyolefin heat-shrink tubing. It can be fixed to the alarm circuit by rotation and connected to the alarm circuit via a magnetic connector. The tube is adjustable in length, allowing the probe to be positioned deeper into the wing tanks.

[0025] The light-emitting diode D1 is used to receive the electrical signal transmitted by the probe circuit. It will emit light to different degrees according to the voltage and frequency, allowing the user to judge the leakage status of the soft oil tank.

[0026] Because the device is sensitive to signals, all wires are wires with metal shielding. During use, the device should be fixed and not held in the hand to prevent vibration from interfering with the instrument's signal collection. Therefore, double-sided foam tape is attached to the bottom of the alarm terminal to fix it to the fuselage or wing.

[0027] The advantages and benefits of the present invention are as follows: The traditional method for inspecting wing fuel tanks involves injecting air into the soft tank and measuring the pressure drop over time using a pressure gauge. If a leak is detected, the soft tank must be removed from the aircraft, and a swelling and shrinking fluid must be applied to the tank. The leak is then located by allowing the tank to sit for a period of time.

[0028] The utility model can solve the shortcomings of the current soft tank sealing detection, such as the long labor cycle for air tightness detection and oil tightness detection caused by the narrow space of the wing tank, and the difficulty in finding the leakage point when the sealing is poor.

[0029] The circuit of the utility model can freely penetrate into various positions of the fuel tank structure through the universal tube and detect gas leaks by acoustic and electrical means. It has the advantages of simple method, low cost, improved production efficiency and improved testing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The circuit of the present invention has a housing.

[0031] Figure 2 This is a circuit diagram of the fuel tank gas leakage detection device of the present invention.

[0032] Among them: 1-detection end, 2-universal tube. DETAILED DESCRIPTION

[0033] The disclosed examples will be described more fully with reference to the accompanying drawings, in which some (but not all) of the disclosed examples are shown. In fact, many different examples can be described and these examples should not be construed as limited to the examples set forth herein. Instead, these examples are described so that this disclosure will be thorough and complete and will fully convey the scope of the disclosure to those skilled in the art.

[0034] like Figure 1 and 2 As shown, a fuel tank sealing detection circuit based on the KD28 chip is provided, including an acoustic probe HTD, resistors R1 to R14, capacitors C1 to C15, transistors VT1 to VT3, a sliding rheostat KP and a KD28 chip, a 9V power supply, a switch S, a resistor R15 and a light-emitting diode;

[0035] The pins of the KD28 chip are connected as follows: pin 4 is connected to the positive electrode of the battery, and pin 4 is connected to the negative electrode of the power supply through capacitor C12; pin 4 is connected to the source of VT1 through resistor R12, resistor R4, and resistor R2 in sequence;

[0036] The 5th pin is connected to the negative terminal of the battery through capacitor C13, resistor R15, light-emitting diode D1, and switch S in sequence; the 5th pin is connected to the negative terminal of light-emitting diode D1 through capacitor C13, capacitor C16, and resistor R13 in sequence;

[0037] The third pin is connected to the cathode of the light-emitting diode D1 through capacitor C14, capacitor C15, and resistor R13 in sequence; the third pin is connected to the eighth pin through capacitor C14;

[0038] Pin 6 is connected to the cathode of light-emitting diode D1 through capacitor C10;

[0039] Pin 7 is connected to the negative pole of the power supply through capacitor C11;

[0040] Pin 1 is connected to the sliding output terminal of the sliding resistor KP through capacitor C9;

[0041] One end of the sliding rheostat KP is connected to the cathode of the light-emitting diode D1, and the other end is connected to the collector of VT3 via capacitor C7; one end of the capacitor C5, one end of the resistor R6 and one end of the resistor R9 are all connected between the resistor R4 and the resistor R12, the other end of the capacitor C5 is connected to the cathode of the power supply, the other end of the resistor R6 is connected to the collector of the transistor VT2, the other end of the resistor R9 is connected to the collector of the transistor VT3, and the collector of the transistor VT2 is connected to the collector of VT3 via C6; the emitter of the transistor VT3 is connected to the cathode of the light-emitting diode D1 via resistors R10 and R11 in sequence; the emitter of the transistor VT2 is connected to the cathode of the light-emitting diode D1 via resistor R7; the collector of the transistor VT2 is connected to the base of VT3;

[0042] A resistor R3 and a capacitor C4 are connected in parallel between the drain of transistor VT1 and the cathode of light-emitting diode D1; the source of transistor VT1 is connected to the base of VT2 via capacitor C3, the base of transistor VT2 is connected to the cathode of light-emitting diode D1 via R5, and the base of transistor VT2 is connected to the cathode of light-emitting diode D1 via resistor R8 and capacitor C8 in sequence;

[0043] One end of capacitor C2 is connected between resistor R4 and resistor R2, and the other end of capacitor C2 is connected to the negative pole of the power supply;

[0044] The positive electrode of the acoustic and electrical probe HTD is connected to the gate of the transistor VT1 through the capacitor C1, and the negative electrode of the acoustic and electrical probe HTD is connected to the negative electrode of the light-emitting diode D1; the gate of the transistor VT1 is connected to the negative electrode of the light-emitting diode D1 through the resistor R1.

[0045] The power source is a 9V battery.

[0046] Transistor VT1 is a 3DJ6 type field effect transistor.

[0047] The acoustic-electric probe is a piezoelectric ceramic piece.

[0048] Transistor VT2 and transistor VT3 are low-noise NPN silicon tubes 3DG6.

[0049] The acoustic and electrical probe collects signals through a universal tube.

[0050] The fuel tank sealing detection circuit based on the KD28 chip is an integrated circuit and is installed in a housing. The housing is connected to a universal tube, one end of which leads to the acoustic and electrical probe HTD, and the other end serves as a detection end extending into the fuel tank.

[0051] During actual operation, after the soft fuel tanks are installed, leak detection is performed in a soundproofed workshop. The operator first secures the wing soft fuel tank leak detection device to the wing panel, then inserts the probe into different locations on the wing tanks and gently squeezes the tanks. If a leak is detected, the alarm circuit's LED will flash at varying brightness and frequencies based on the amplitude and frequency of the electrical signal, allowing the operator to determine the leak status of the aircraft's wing soft fuel tanks.

[0052] The description of various advantageous arrangements has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the examples disclosed. Many modifications and variations will be apparent to those skilled in the art. In addition, different advantageous examples may describe different advantages compared to other advantageous examples. The selected example or examples are chosen and described to best illustrate the principles of the examples, their practical application, and to enable those skilled in the art to understand the disclosure with various examples with various modifications suitable for the particular use contemplated.

Claims

1. A wing fuel tank leak detection circuit, characterized by: It includes an acoustic and electric probe HTD, resistors R1 to R15, capacitors C1 to C16, transistors VT1 to VT3, a sliding rheostat KP and a KD28 chip, a 9V power supply, a switch S and a light-emitting diode D1; The pins of the KD28 chip are connected as follows: pin 4 is connected to the positive electrode of the battery, and pin 4 is connected to the negative electrode of the power supply through capacitor C12; pin 4 is connected to the source of VT1 through resistor R12, resistor R4, and resistor R2 in sequence; The 5th pin is connected to the negative terminal of the battery through capacitor C13, resistor R15, light-emitting diode D1, and switch S in sequence; the 5th pin is connected to the negative terminal of light-emitting diode D1 through capacitor C13, capacitor C16, and resistor R13 in sequence; The third pin is connected to the cathode of the light-emitting diode D1 through capacitor C14, capacitor C15, and resistor R13 in sequence; the third pin is connected to the eighth pin through capacitor C14; Pin 6 is connected to the cathode of light-emitting diode D1 through capacitor C10; Pin 7 is connected to the negative pole of the power supply through capacitor C11; Pin 1 is connected to the sliding output terminal of the sliding resistor KP through capacitor C9; One end of the sliding rheostat KP is connected to the cathode of the light-emitting diode D1, and the other end is connected to the collector of VT3 via capacitor C7; one end of the capacitor C5, one end of the resistor R6 and one end of the resistor R9 are all connected between the resistor R4 and the resistor R12, the other end of the capacitor C5 is connected to the cathode of the power supply, the other end of the resistor R6 is connected to the collector of the transistor VT2, the other end of the resistor R9 is connected to the collector of the transistor VT3, and the collector of the transistor VT2 is connected to the collector of VT3 via C6; the emitter of the transistor VT3 is connected to the cathode of the light-emitting diode D1 via resistors R10 and R11 in sequence; the emitter of the transistor VT2 is connected to the cathode of the light-emitting diode D1 via resistor R7; the collector of the transistor VT2 is connected to the base of VT3; A resistor R3 and a capacitor C4 are connected in parallel between the drain of transistor VT1 and the cathode of light-emitting diode D1; the source of transistor VT1 is connected to the base of VT2 via capacitor C3, the base of transistor VT2 is connected to the cathode of light-emitting diode D1 via R5, and the base of transistor VT2 is connected to the cathode of light-emitting diode D1 via resistor R8 and capacitor C8 in sequence; One end of capacitor C2 is connected between resistor R4 and resistor R2, and the other end of capacitor C2 is connected to the negative pole of the power supply; The positive electrode of the acoustic and electrical probe HTD is connected to the gate of the transistor VT1 through the capacitor C1, and the negative electrode of the acoustic and electrical probe HTD is connected to the negative electrode of the light-emitting diode D1; the gate of the transistor VT1 is connected to the negative electrode of the light-emitting diode D1 through the resistor R1.

2. The wing fuel tank air leakage detection circuit according to claim 1, characterized in that: The power source is a 9V battery.

3. The wing fuel tank air leakage detection circuit according to claim 1, characterized in that: Transistor VT1 is a 3DJ6 type field effect transistor.

4. The wing fuel tank air leakage detection circuit according to claim 1, characterized in that: The acoustic-electric probe is a piezoelectric ceramic piece.

5. The wing fuel tank air leakage detection circuit according to claim 1, characterized in that: Transistor VT2 and transistor VT3 are low-noise NPN silicon tubes 3DG6.

6. The wing fuel tank air leakage detection circuit according to claim 1, characterized in that: The acoustic and electrical probe collects signals through a universal tube.

7. The wing fuel tank air leakage detection circuit according to claim 1, characterized in that: The wing soft oil tank air leakage detection circuit is an integrated circuit and is installed in a shell. The shell is connected to a universal tube. One end of the universal tube leads to the acoustic and electrical probe HTD, and the other end serves as a detection end extending into the oil tank.

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