There is no limit to creativity, and the instrument is invented. Today we introduce a patent for a national invention patent - contact oil level measuring transducer. The patent was applied for by Sichuan Fanhua Aviation Instrument Electric Co., Ltd. and was authorized to be announced on March 22, 2017.
Description
The utility model relates to a contact type oil level measuring transducer which is mainly used for measuring the fuel level of an aircraft and the fuel temperature.
Background of the invention
The capacitive oil level sensor uses a capacitance formed by filling the liquid medium between the positive and negative probes to linearly change the liquid level, and converts the amount of change in capacitance (ie, the amount of change in the liquid level) into a standard electrical signal output. Generally, the sensing portion of the general capacitive oil level measuring sensor is a coaxial container, which causes a change in the capacitance between the sensor tube and the sensing electrode when the oil enters the container. This variation is performed by the conversion of the temperature compensation circuit. Linear and temperature compensation, output 4 ~ 20mA or 0 ~ 5V standard signal supply to the display instrument. Because the analog components such as bidirectional switches and operational amplifiers in the circuit are susceptible to temperature changes in the operating environment, the output of the circuit has a large temperature drift. Such temperature drift value has a great influence on the accuracy of measuring the fuel level of the aircraft fuel, so it needs to be compensated. In general, the output voltage of the capacitance measuring circuit changes with temperature, and the temperature compensation is used to reduce the temperature drift.
In the prior art, a capacitive sensor for measuring the fuel level of an aircraft has the following disadvantages: (1) The sensor does not have a fuel temperature measuring component, and thus cannot compensate for the error caused by the fuel oil level measurement due to the fuel temperature change. (2) The positioning method between the sensors is generally composed of a plurality of concentric positioning pins with a vertical space, which has the problems of poor processability and low positioning accuracy. (3) Fuel contaminants are often deposited on the jacket sheets mounted on both ends of the sensor, resulting in a sensor that is heavily out of capacitance and produces a large parasitic capacitance value. (4) After the cable in the fuel tank is connected to the signal output end of the sensor, there is no effective stress buffering device. In the aircraft use environment, the swing of the wire has a greater impact on the lug or the connecting ring connected to the terminal. It is easy to cause the connection to be loose.
Summary of the invention
The purpose of the utility model is to provide a concentric defect with high precision and strong shock resistance, which can reduce the parasitic capacitance value in the dry capacitance value of the sensor and compensate the fuel caused by the temperature change of the fuel. Oil level measurement error, contact type oil level measuring transducer that solves the above problems in structure and function.
The technical solution adopted by the utility model to solve the technical problem thereof is: a contact type oil level measuring transmitter, comprising: an oil level measuring module 4 composed of three metal tubes integrally assembled into one body and fixed at the oil level The temperature compensation module 9 at the bottom end of the height measuring module is characterized in that the outer metal pipe body 10 serves as a shield outer pipe of the entire sensor and a fixed support function, and the output of the middle metal pipe body 11 and the inner metal pipe body 12 and the oil immersion height are formed. The ratio of the oil level height signal capacitance value C, and the three metal tube bodies are distributed in three spaces, the inner liner 13, the outer liner 15 and the pin 14 are vertically positioned at the upper and lower positions, and the bottom end is guided. The rod 5 and the aluminum tray 7 are coaxially fixed with a temperature compensation module 9, and the temperature compensation module 9 is fixed at the center of the bottom end of the metal pipe body through the aluminum tray 7 and the guide rod 5, and the wiring sleeve 16 will measure the capacitance of the oil level height measuring module 4. The value C and the resistance value R of the temperature compensation module 9 are output through the guide rod 5 in the tube body, and will be converted into a current signal IC and IR proportional to the capacitance C and the resistance value R, and the socket connected through the shielded wire (17) (19) transmission to combustion
Figure is the main view of the contact type oil level measuring transducer of the utility model
Compared with the prior art, the utility model has the following beneficial effects: high concentric positioning accuracy. The three metal pipe bodies of the utility model are three-dimensionally distributed in a space, and the inner liner 13, the outer liner 15 and the pin 14 which are spaced apart from each other are radially positioned; each of the three is uniformly distributed in the same radial plane. The inner liner 13, the outer liner 15 and the pin 14 are assembled in the axial direction at intervals of two more, a total of nine sets for ensuring concentric mounting of the metal pipe body. A coaxial temperature compensation module 9 is fixed at the bottom end via a guide rod 5 and an aluminum tray 7. The utility model has the advantages of simple structure, high concentric positioning precision, and the positioning mode of the sensor between the tubes adopts the component positioning mode of the new structure, and the processability is good, and the problem that the concentric positioning accuracy of the sensor is not high can be solved. No moving or elastic components, high impact resistance, high precision, stable performance; easy installation, high reliability, and minimal maintenance. Under normal circumstances, no maintenance is required. The temperature compensation module 9 passes through the aluminum tray 7 and the guide bar 5.
It can reduce the parasitic capacitance value in the sensor dry capacitance value. The utility model fixes the temperature compensation module 9 to the positive central bottom end of the metal pipe body, accurately compensates the temperature drift of the output, and simultaneously uses the aluminum bushing 8, the two pipe bushings 3 and the three concentric metal pipe bodies to the temperature compensation module 9 Protection, at the same time, can play the role of lightning protection, thus eliminating the impact of fuel pollutants on the effective capacitance of the sensor. The inner two metal pipes 11 and 12 measure the oil level height signal, and the outermost metal pipe 10 is used to shield the external interference signal, and the capacitance value C of the oil level measuring module 4 and the resistance value R of the temperature compensation module 9 Through the output of the guide rod 5 in the pipe body, the current signal IC and IR are converted into a fuel measurement control system proportional to C and R, and the fuel oil level measurement error is compensated by the temperature compensation module 9, thereby reducing the sensor. The parasitic capacitance value in the dry capacitance value can effectively measure the temperature change of the fuel tank and eliminate the error caused by the thermal expansion and contraction of the fuel medium. The sensor adds temperature compensation to automatically correct for errors due to temperature differences. With precise temperature compensation and linear correction, it has the advantages of high precision, high stability and continuous measurement. It can directly obtain the fuel consumption value by measuring the oil volume of the fuel tank, and does not have any effect or influence on the oil system/pipe. And the measured value is not affected by the temperature and specific gravity of the liquid to be tested, and the shape and pressure of the container. The temperature compensation module uses a highly integrated dedicated IC chip, which is converted into a standard signal that can be recognized by a computer or the like through precise temperature compensation and linear correction. The capacitive liquid level sensor has a field calibration function, and the user can perform zero point, arbitrary truncation length, The range is automatically calibrated to suit a variety of harsh or complex applications.
Improved shock resistance. The utility model uses three mutually insulated coaxial metal pipe bodies to form an oil level height measuring module 4, wherein the outermost layer acts as a shielding pipe to block external interference signals, the inner two-layer pipe measures the oil level signal, and the bottom end is fixed coaxially. The temperature compensation module 9 relies on the change of the medium in the measuring sensor to obtain the height and the oil quantity of the oil level, and implements the temperature compensation and the inclination compensation. The experimental results show that the measurement and display can be accurately linearized by the full range, and the anti-interference ability Extremely strong, able to withstand 20,000 volts of high-voltage sparks for 30 seconds, inverters, high-power radios and other strong interference equipment to measure their results. The axial relative movement between the three concentric metal pipes 10, 11 and 12 under vibration conditions on the aircraft is effectively prevented by the two pipe bushings 3 and the adjusting washer 1 installed at both ends of the metal pipe body. Sealing treatment is adopted between the guide rod 5 and the inner metal pipe body 12, and the two pipe bushings 3 and the aluminum bushing 8 are simultaneously opened in the middle, so that the fuel pollutants immersed in the sensor body can be quickly flowed out to prevent fuel pollution. The material deposition or blocking temperature measurement module, the output signal has a certain damping time, which can eliminate data fluctuation caused by vibration and bump.
The utility model is used for an aircraft fuel measurement control system, and has two functions of fuel oil level height signal measurement and fuel temperature measurement. It can also be used for accurate measurement of oil levels in automobile fuel tanks, tank trucks, railway locomotives, oil depots, etc. It can be installed in various occasions to accurately measure the oil level of gasoline, diesel, hydraulic oil, etc. It can also be used for high temperature oil level measurement.
Article link: China Instrument Network http://
Description
The utility model relates to a contact type oil level measuring transducer which is mainly used for measuring the fuel level of an aircraft and the fuel temperature.
Background of the invention
The capacitive oil level sensor uses a capacitance formed by filling the liquid medium between the positive and negative probes to linearly change the liquid level, and converts the amount of change in capacitance (ie, the amount of change in the liquid level) into a standard electrical signal output. Generally, the sensing portion of the general capacitive oil level measuring sensor is a coaxial container, which causes a change in the capacitance between the sensor tube and the sensing electrode when the oil enters the container. This variation is performed by the conversion of the temperature compensation circuit. Linear and temperature compensation, output 4 ~ 20mA or 0 ~ 5V standard signal supply to the display instrument. Because the analog components such as bidirectional switches and operational amplifiers in the circuit are susceptible to temperature changes in the operating environment, the output of the circuit has a large temperature drift. Such temperature drift value has a great influence on the accuracy of measuring the fuel level of the aircraft fuel, so it needs to be compensated. In general, the output voltage of the capacitance measuring circuit changes with temperature, and the temperature compensation is used to reduce the temperature drift.
In the prior art, a capacitive sensor for measuring the fuel level of an aircraft has the following disadvantages: (1) The sensor does not have a fuel temperature measuring component, and thus cannot compensate for the error caused by the fuel oil level measurement due to the fuel temperature change. (2) The positioning method between the sensors is generally composed of a plurality of concentric positioning pins with a vertical space, which has the problems of poor processability and low positioning accuracy. (3) Fuel contaminants are often deposited on the jacket sheets mounted on both ends of the sensor, resulting in a sensor that is heavily out of capacitance and produces a large parasitic capacitance value. (4) After the cable in the fuel tank is connected to the signal output end of the sensor, there is no effective stress buffering device. In the aircraft use environment, the swing of the wire has a greater impact on the lug or the connecting ring connected to the terminal. It is easy to cause the connection to be loose.
Summary of the invention
The purpose of the utility model is to provide a concentric defect with high precision and strong shock resistance, which can reduce the parasitic capacitance value in the dry capacitance value of the sensor and compensate the fuel caused by the temperature change of the fuel. Oil level measurement error, contact type oil level measuring transducer that solves the above problems in structure and function.
The technical solution adopted by the utility model to solve the technical problem thereof is: a contact type oil level measuring transmitter, comprising: an oil level measuring module 4 composed of three metal tubes integrally assembled into one body and fixed at the oil level The temperature compensation module 9 at the bottom end of the height measuring module is characterized in that the outer metal pipe body 10 serves as a shield outer pipe of the entire sensor and a fixed support function, and the output of the middle metal pipe body 11 and the inner metal pipe body 12 and the oil immersion height are formed. The ratio of the oil level height signal capacitance value C, and the three metal tube bodies are distributed in three spaces, the inner liner 13, the outer liner 15 and the pin 14 are vertically positioned at the upper and lower positions, and the bottom end is guided. The rod 5 and the aluminum tray 7 are coaxially fixed with a temperature compensation module 9, and the temperature compensation module 9 is fixed at the center of the bottom end of the metal pipe body through the aluminum tray 7 and the guide rod 5, and the wiring sleeve 16 will measure the capacitance of the oil level height measuring module 4. The value C and the resistance value R of the temperature compensation module 9 are output through the guide rod 5 in the tube body, and will be converted into a current signal IC and IR proportional to the capacitance C and the resistance value R, and the socket connected through the shielded wire (17) (19) transmission to combustion
Figure is the main view of the contact type oil level measuring transducer of the utility model
Compared with the prior art, the utility model has the following beneficial effects: high concentric positioning accuracy. The three metal pipe bodies of the utility model are three-dimensionally distributed in a space, and the inner liner 13, the outer liner 15 and the pin 14 which are spaced apart from each other are radially positioned; each of the three is uniformly distributed in the same radial plane. The inner liner 13, the outer liner 15 and the pin 14 are assembled in the axial direction at intervals of two more, a total of nine sets for ensuring concentric mounting of the metal pipe body. A coaxial temperature compensation module 9 is fixed at the bottom end via a guide rod 5 and an aluminum tray 7. The utility model has the advantages of simple structure, high concentric positioning precision, and the positioning mode of the sensor between the tubes adopts the component positioning mode of the new structure, and the processability is good, and the problem that the concentric positioning accuracy of the sensor is not high can be solved. No moving or elastic components, high impact resistance, high precision, stable performance; easy installation, high reliability, and minimal maintenance. Under normal circumstances, no maintenance is required. The temperature compensation module 9 passes through the aluminum tray 7 and the guide bar 5.
It can reduce the parasitic capacitance value in the sensor dry capacitance value. The utility model fixes the temperature compensation module 9 to the positive central bottom end of the metal pipe body, accurately compensates the temperature drift of the output, and simultaneously uses the aluminum bushing 8, the two pipe bushings 3 and the three concentric metal pipe bodies to the temperature compensation module 9 Protection, at the same time, can play the role of lightning protection, thus eliminating the impact of fuel pollutants on the effective capacitance of the sensor. The inner two metal pipes 11 and 12 measure the oil level height signal, and the outermost metal pipe 10 is used to shield the external interference signal, and the capacitance value C of the oil level measuring module 4 and the resistance value R of the temperature compensation module 9 Through the output of the guide rod 5 in the pipe body, the current signal IC and IR are converted into a fuel measurement control system proportional to C and R, and the fuel oil level measurement error is compensated by the temperature compensation module 9, thereby reducing the sensor. The parasitic capacitance value in the dry capacitance value can effectively measure the temperature change of the fuel tank and eliminate the error caused by the thermal expansion and contraction of the fuel medium. The sensor adds temperature compensation to automatically correct for errors due to temperature differences. With precise temperature compensation and linear correction, it has the advantages of high precision, high stability and continuous measurement. It can directly obtain the fuel consumption value by measuring the oil volume of the fuel tank, and does not have any effect or influence on the oil system/pipe. And the measured value is not affected by the temperature and specific gravity of the liquid to be tested, and the shape and pressure of the container. The temperature compensation module uses a highly integrated dedicated IC chip, which is converted into a standard signal that can be recognized by a computer or the like through precise temperature compensation and linear correction. The capacitive liquid level sensor has a field calibration function, and the user can perform zero point, arbitrary truncation length, The range is automatically calibrated to suit a variety of harsh or complex applications.
Improved shock resistance. The utility model uses three mutually insulated coaxial metal pipe bodies to form an oil level height measuring module 4, wherein the outermost layer acts as a shielding pipe to block external interference signals, the inner two-layer pipe measures the oil level signal, and the bottom end is fixed coaxially. The temperature compensation module 9 relies on the change of the medium in the measuring sensor to obtain the height and the oil quantity of the oil level, and implements the temperature compensation and the inclination compensation. The experimental results show that the measurement and display can be accurately linearized by the full range, and the anti-interference ability Extremely strong, able to withstand 20,000 volts of high-voltage sparks for 30 seconds, inverters, high-power radios and other strong interference equipment to measure their results. The axial relative movement between the three concentric metal pipes 10, 11 and 12 under vibration conditions on the aircraft is effectively prevented by the two pipe bushings 3 and the adjusting washer 1 installed at both ends of the metal pipe body. Sealing treatment is adopted between the guide rod 5 and the inner metal pipe body 12, and the two pipe bushings 3 and the aluminum bushing 8 are simultaneously opened in the middle, so that the fuel pollutants immersed in the sensor body can be quickly flowed out to prevent fuel pollution. The material deposition or blocking temperature measurement module, the output signal has a certain damping time, which can eliminate data fluctuation caused by vibration and bump.
The utility model is used for an aircraft fuel measurement control system, and has two functions of fuel oil level height signal measurement and fuel temperature measurement. It can also be used for accurate measurement of oil levels in automobile fuel tanks, tank trucks, railway locomotives, oil depots, etc. It can be installed in various occasions to accurately measure the oil level of gasoline, diesel, hydraulic oil, etc. It can also be used for high temperature oil level measurement.
Article link: China Instrument Network http://
Jiangmen Hongli Energy Co.ltd , https://www.honglienergy.com