A sensor for detecting the ethanol content of gasoline

Abstract

The utility model discloses a sensor for detecting ethanol content in gasoline, including outer package shell, condenser pipe and electric control unit, the bottom of outer package shell is equipped with condenser installation cavity, the condenser pipe is fixed in this condenser installation cavity, the condenser pipe includes condenser outer tube and condenser inner tube, the condenser outer tube is covered in condenser inner tube, both are the through pipe design of two ends opening, and the capacitor structure is formed to the isolated setting between both, the electric control unit is located in the outer package shell, with the condenser outer tube is connected through condenser outer tube lead line, with the condenser inner tube is connected through condenser inner tube lead line. Utilize the dielectric constant of different component proportion of fuel to be inconsistent, to cause the characteristic of inconsistent capacitance, get the accurate content of ethanol in fuel through the measurement of capacitor back -propagation, can avoid environmental factor to cause the influence to the detection result, and the back -propagation process is the fixed cover type calculation, and the calculation is small, and data processing is simple, and will not be because data calculation appears deviation.

Description

Technical Field

[0001] The embodiments of this utility model belong to the field of gasoline detection technology, and more specifically, relate to a sensor for detecting the ethanol content in gasoline. Background Technology

[0002] Gasoline is a fossil fuel and a non-renewable resource. China's domestic oil reserves are limited, and the country relies heavily on imports. Ethanol, on the other hand, is a renewable resource and can replace some gasoline. Promoting the use of ethanol fuel can reduce dependence on petroleum. Currently, the main method for using ethanol fuel is to add a portion of ethanol to gasoline to create ethanol gasoline. However, when using ethanol gasoline, the ethanol content needs to be monitored to control injection parameters, ensuring complete combustion of ethanol and gasoline, optimizing engine efficiency, and improving engine performance. In actual use, it is impossible to guarantee that the ethanol content in ethanol gasoline remains constant; therefore, real-time monitoring of the fuel entering the engine is necessary for precise control.

[0003] In existing technologies, photoelectric signals are generally used to detect the ethanol content in fuels, typically using a nanocatalytic luminescence detector. A voltage is applied across the nanomaterial, and the resulting current is used as the detection signal. The detector has a positive electrode and a negative electrode at each end of the nano-semiconductor metal oxide. The current output and photoelectric signal conversion device between the positive and negative electrodes are connected to the electrical signal detection circuit.

[0004] Existing detection methods can rapidly and accurately detect the ethanol content in gasoline. However, measurements using photoelectric signals are susceptible to environmental interference and require algorithms for noise reduction and compensation, resulting in significant measurement errors. Therefore, a sensor is needed to detect the ethanol content in gasoline by using capacitance, thereby improving accuracy and reducing costs. Utility Model Content

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this utility model provides a sensor for detecting the ethanol content in gasoline. By isolating the outer and inner capacitor tubes, a capacitor structure is formed between them. When ethanol-containing gasoline passes through this capacitor tube, an oscillating circuit charges and discharges the capacitor tube. Simultaneously, a microprocessor captures the output frequency of the capacitor tube and calculates its time constant and capacitance, thereby deducing the corresponding fuel component ratio. Utilizing the characteristic that different fuel component ratios have different dielectric constants, resulting in different capacitances, the accurate ethanol content in the fuel is deduced by measuring the capacitance. This avoids the influence of environmental factors on the detection results. Furthermore, the deduction process is a fixed nested calculation, with low computational load and simple data processing, preventing deviations due to data calculation errors.

[0006] To achieve the above objectives, this utility model provides a sensor for detecting the ethanol content in gasoline, including an outer casing, a capacitor, and an electronic control unit; The bottom of the outer casing is provided with a capacitor mounting cavity, and the capacitor tube is fixed in the capacitor mounting cavity; The capacitor tube includes an outer capacitor tube and an inner capacitor tube. The outer capacitor tube is sleeved outside the inner capacitor tube. Both are open tubes at both ends and are isolated from each other to form a capacitor structure. The electronic control unit is located in the outer casing and is connected to the outer tube of the capacitor via an outer tube lead, and to the inner tube of the capacitor via an inner tube lead.

[0007] Furthermore, the inner wall of the capacitor mounting cavity is an arc surface with the same radius as the outer diameter of the capacitor outer tube, and the capacitor outer tube is embedded in the capacitor mounting cavity; The outer casing also includes a fixing cavity, which is in communication with the capacitor mounting cavity.

[0008] Furthermore, the outer tube of the capacitor has a through hole on its side wall near the fixed cavity, which serves as the inner hole of the outer tube. The inner tube of the capacitor has an inner tube protrusion protruding outward at the same position. The inner tube protrusion is located in the inner hole of the outer tube. The connection between the two allows the inner tube of the capacitor to be suspended inside the outer tube of the capacitor, thus avoiding contact between the inner tube and the outer tube of the capacitor.

[0009] Furthermore, an isolation ring is provided between the inner tube protrusion and the inner hole of the outer tube. This isolation ring isolates the connection between the inner tube protrusion and the inner hole of the outer tube, so that capacitance can be generated smoothly between the outer tube and the inner tube of the capacitor.

[0010] Furthermore, the fixing cavity is filled with potting compound, which, after curing, together with the inner wall of the capacitor mounting cavity, provides a limiting effect on the capacitor tube.

[0011] Furthermore, a mounting platform is provided on the side of the fixed cavity away from the capacitor mounting cavity, the electronic control unit is fixed on the mounting platform, and the capacitor outer tube lead and the capacitor inner tube lead pass through the fixed cavity and are connected to the electronic control unit.

[0012] Furthermore, a sealed cavity is provided on the other side of the electronic control unit, which is also filled with potting compound. A sealing cover is also provided at the port of the sealed cavity, and the sealing cover is detachably connected to the outer shell.

[0013] Furthermore, one side of the outer casing is provided with an external insertion port, through which a plug is provided, which is connected to the electronic control unit.

[0014] In summary, compared with the prior art, the above-described technical solution conceived by this utility model can achieve the following beneficial effects: 1. This utility model discloses a sensor for detecting the ethanol content in gasoline. By isolating the outer and inner capacitor tubes, a capacitor structure is formed between them. When ethanol-containing gasoline passes through the capacitor tube, an oscillating circuit charges and discharges the capacitor tube. Simultaneously, a microprocessor captures the output frequency of the capacitor tube and calculates its time constant and capacitance, thereby deducing the corresponding fuel component ratio. Utilizing the characteristic that different fuel component ratios have different dielectric constants, resulting in different capacitances, the accurate ethanol content in the fuel is deduced by measuring the capacitance. This avoids the influence of environmental factors on the detection results. Furthermore, the deduction process is a fixed nested calculation, with low computational load and simple data processing, preventing deviations due to data calculation errors.

[0015] 2. The sensor of this utility model for detecting the ethanol content in gasoline has a boss extending from the outer side of the inner hole of the outer tube into the fixed cavity. The isolation ring extends beyond the boss, and the inner tube protrusion extends beyond the isolation ring. That is, the boss, the isolation ring, and the inner tube protrusion are all in contact with the potting compound in the fixed cavity, thereby reinforcing all three.

[0016] 3. The sensor of this utility model for detecting the ethanol content in gasoline connects the signal output and power supply of the electronic control unit to an external connector via a plug. The external connector is connected to equipment including the vehicle computer and the upper unit. After receiving the signal, these devices control the relevant parameters of fuel injection to ensure the complete combustion of ethanol and gasoline, optimize and improve engine efficiency, and enhance engine performance. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the outer shell structure of a sensor for detecting the ethanol content in gasoline according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a sensor for detecting the ethanol content in gasoline according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a capacitor tube structure for a sensor used to detect the ethanol content in gasoline, according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the electronic control unit circuit of a sensor for detecting the ethanol content in gasoline, according to an embodiment of the present invention.

[0018] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1-outer casing, 101-capacitor mounting cavity, 102-fixed cavity, 103-sealed cavity, 104-external socket, 2-capacitor tube, 201-outer capacitor tube, 202-inner capacitor tube, 203-inner hole of outer tube, 204-protrusion of inner tube, 205-isolation ring, 3-electronic control unit, 4-insertion plate, 5-sealing cap, 6-potting compound, 7-lead wire of outer capacitor tube, 8-lead wire of inner capacitor tube. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0020] like Figure 1-3 As shown, this embodiment of the present invention provides a sensor for detecting the ethanol content in gasoline, comprising an outer shell 1, a capacitor tube 2 fixed on the outer shell 1, and an electronic control unit 3 disposed in the outer shell 1 and connected to the capacitor tube 2 via leads. The bottom of the outer shell 1 has a capacitor mounting cavity 101, in which the capacitor tube 2 is fixed. The capacitor tube 2 includes an outer capacitor tube 201 and an inner capacitor tube 202. The outer capacitor tube 201 is fitted over the inner capacitor tube 202. Both are open-ended tubes and are isolated from each other. The outer capacitor tube 201 is connected to the electronic control unit 3 via an outer capacitor tube lead 7, and the inner capacitor tube 202 is connected to the electronic control unit 3 via an inner capacitor tube lead 8. The electronic control unit 3 includes an oscillation circuit and a microprocessor. The oscillation circuit continuously charges and discharges the capacitor tube 2, and the microprocessor captures the frequency output by the capacitor tube 2. By isolating the outer capacitor tube 201 and the inner capacitor tube 202, a capacitor structure is formed between them. When ethanol gasoline passes through this capacitor tube 2, the oscillation circuit charges and discharges the capacitor tube 2. Simultaneously, the microprocessor captures the output frequency of the capacitor tube 2 and calculates its time constant and capacitance, thereby deducing the corresponding fuel composition ratio. Utilizing the characteristic that different fuel composition ratios have different dielectric constants, resulting in different capacitances, the accurate ethanol content in the fuel can be deduced by measuring the capacitance. This avoids the influence of environmental factors on the detection results. Furthermore, the deduction process is a fixed nested calculation, with low computational load and simple data processing, preventing deviations due to data calculation errors.

[0021] like Figure 2As shown, the inner wall of the capacitor mounting cavity 101 is an arc surface, and its radius is the same as the outer diameter of the capacitor outer tube 201. The capacitor outer tube 201 is embedded in the capacitor mounting cavity 101. The outer shell 1 also includes a fixing cavity 102, which is connected to the capacitor mounting cavity 101.

[0022] like Figure 3 As shown, the outer tube 201 of the capacitor has a through hole on its side wall near the fixed cavity 102, serving as the inner hole 203 of the outer tube. At the same position, the inner tube 202 has an inner tube protrusion 204 protruding outwards. The inner tube protrusion 204 is located within the inner hole 203 of the outer tube. The connection between the two allows the inner tube 202 to suspend within the outer tube 201, preventing contact between them.

[0023] As a further preferred embodiment, to secure the capacitor tube 2 within the capacitor mounting cavity 101, a potting compound 6 is filled into the fixing cavity 102. After curing, the potting compound 6, together with the inner wall of the capacitor mounting cavity 101, provides a limiting effect on the capacitor tube 2. Furthermore, a boss extends from the outer side of the inner hole 203 into the fixing cavity 102, with the isolation ring 205 extending beyond this boss and the inner tube protrusion 204 extending beyond the isolation ring 205. That is, the boss, the isolation ring 205, and the inner tube protrusion 204 all contact the potting compound 6 in the fixing cavity 102, thereby reinforcing all three.

[0024] The fixed cavity 102 is provided with a mounting platform on the side away from the capacitor mounting cavity 101. The electronic control unit 3 is fixed to the mounting platform by screws. The capacitor outer tube lead 7 and the capacitor inner tube lead 8 pass through the fixed cavity 102 and are connected to the electronic control unit 3. Both leads are fixed in the fixed cavity 102 by potting compound 6 to prevent vibration from causing them to shake and eventually cause the connection point to fall off.

[0025] On the other side of the electronic control unit 3, there is also a sealed cavity 103, which is also filled with potting compound 6 to provide dust and water protection for the electronic control unit 3. A sealing cover 5 is also provided at the port of the sealed cavity 103, and the sealing cover 5 is detachably connected to the outer shell 1 by means including snap-fit ​​and interference fit.

[0026] As a further preferred embodiment, one side of the outer casing 1 is provided with an external connector 104, and a connector 4 is provided in the external connector 104, which is connected to the electronic control unit 3. The signal output and power supply of the electronic control unit 3 are connected to the external connector 104 through the connector 4. The external connector 104 is connected to equipment including the on-board computer and the upper control unit. After receiving the signal, these devices control the relevant parameters of fuel injection to ensure the complete combustion of ethanol and gasoline, optimize and improve engine efficiency, and improve engine performance.

[0027] like Figure 4 As shown, the electronic control unit 3 also includes a temperature measurement circuit. When the temperature changes, the resistance value of the NTC resistor changes, which in turn changes the time constant, ultimately altering the time constant and the output frequency. By capturing the frequency signal through a microprocessor, the current temperature can be calculated. The dielectric constant of the mixed fuel varies at different temperatures. During calibration, the capacitance, frequency, and temperature values ​​of the mixed fuel are recorded simultaneously and programmed into the electronic control unit's microprocessor. The microprocessor then looks up the capacitance and frequency values ​​at different temperatures in a table, thus deducing the fuel composition at the current temperature. This method is more accurate and has a wider applicable temperature range.

[0028] The electronic control unit 3 also includes an analog switch and a time-division selection control circuit, which can select and connect the input channels of relevant signals according to needs, and send them to the microprocessor for processing, thereby expanding the number of signal acquisition channels.

[0029] The electronic control unit 3 also includes a frequency divider circuit. When the oscillation frequency is too high and sampling is difficult, the frequency can be reduced by the frequency divider, so as to capture the signal frequency more accurately.

[0030] It is understandable that when there are deviations in the manufacturing process of the capacitor tube, the equivalent capacitance will also be different. The calibration capacitor can be adjusted by the capacitor fine-tuning calibration circuit in the electronic control unit to compensate for the difference, thereby ensuring that the initial capacitance is the same and ensuring consistent accuracy.

[0031] In harsh working environments, such as high temperature, high pressure, or environments with corrosive gases, sealing performance may be affected. Multiple sealing structures can be added between the sealing cap and the outer shell. This invention designs a novel sealing structure at the connection between the sealing cap and the outer shell. The inner edge of the sealing cap has an annular sealing groove, within which an annular sealing strip is embedded. The sealing strip is made of highly elastic silicone rubber and coated with a nano-waterproof coating, which effectively prevents moisture penetration. When the sealing cap and the outer shell are connected, the sealing strip undergoes elastic deformation under pressure, tightly fitting the sealing end face of the outer shell to form a reliable seal. Simultaneously, the sealing cap and the outer shell are connected using an interference fit, with precise control of the interference amount ensuring a tight connection. Furthermore, an annular waterproof protrusion is provided on the outer side of the sealing cap, which fits tightly against the outer surface of the outer shell, further preventing the intrusion of external moisture and impurities. This multi-layered sealing structure not only improves the sealing performance of the outer casing but also enhances its waterproof and dustproof properties, enabling the sensor to better adapt to various complex working environments and ensuring the normal operation of internal components such as the electronic control unit.

[0032] This invention optimizes the design of the signal transmission line to further reduce signal interference. Specifically, the outer and inner leads of the capacitor employ differential signal transmission. By arranging the signal line and return line closely adjacent to each other, their electromagnetic fields cancel each other out, effectively reducing common-mode interference. Simultaneously, an electromagnetic shielding layer is added to the outer layer of the signal transmission line. This shielding layer is made of highly conductive aluminum alloy and connected to the ground via a grounding terminal, forming a good grounding path and further suppressing external electromagnetic interference. Furthermore, a multi-stage filtering circuit, including a low-pass filter and a band-stop filter, is added inside the electronic control unit. The low-pass filter filters out high-frequency interference signals, ensuring signal purity; the band-stop filter suppresses interference signals within a specific frequency range, further improving signal quality. Through these dual measures, this invention significantly reduces signal interference, improves the stability and accuracy of the measurement signal, and thus enhances the overall performance of the sensor.

[0033] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A sensor for detecting the ethanol content in gasoline, characterized in that, It includes an outer casing (1), a capacitor (2), and an electronic control unit (3); The bottom of the outer shell (1) is provided with a capacitor mounting cavity (101), and the capacitor tube (2) is fixed in the capacitor mounting cavity (101); The capacitor tube (2) includes an outer capacitor tube (201) and an inner capacitor tube (202). The outer capacitor tube (201) is sleeved on the outer capacitor tube (202). Both are open tubes at both ends and are isolated from each other to form a capacitor structure. The electronic control unit (3) is located in the outer casing (1), and is connected to the outer tube of the capacitor (201) through the outer tube lead (7), and to the inner tube of the capacitor (202) through the inner tube lead (8).

2. The sensor for detecting ethanol content in gasoline according to claim 1, characterized in that, The inner wall of the capacitor mounting cavity (101) is an arc surface, and its radius is the same as the outer diameter of the capacitor outer tube (201). The capacitor outer tube (201) is embedded in the capacitor mounting cavity (101). The outer casing (1) also includes a fixing cavity (102), which is connected to the capacitor mounting cavity (101).

3. A sensor for detecting ethanol content in gasoline according to claim 2, characterized in that, The outer tube of the capacitor (201) has a through hole on its side wall near the fixed cavity (102) as an inner hole (203). The inner tube of the capacitor (202) has an inner tube protrusion (204) protruding outward at the same position. The inner tube protrusion (204) is located in the inner hole (203) of the outer tube. The connection between the two allows the inner tube of the capacitor (202) to be suspended in the outer tube of the capacitor (201), thus avoiding contact between the inner tube of the capacitor (202) and the outer tube of the capacitor (201).

4. A sensor for detecting ethanol content in gasoline according to claim 3, characterized in that, An isolation ring (205) is provided between the inner tube protrusion (204) and the outer tube inner hole (203). The connection between the inner tube protrusion (204) and the outer tube inner hole (203) is isolated by the isolation ring (205) so that the capacitor outer tube (201) and the capacitor inner tube (202) can generate capacitance smoothly.

5. A sensor for detecting ethanol content in gasoline according to claim 4, characterized in that, The fixed cavity (102) is filled with potting compound (6), which, after curing, together with the inner wall of the capacitor mounting cavity (101), provides a limit for the capacitor tube (2).

6. A sensor for detecting ethanol content in gasoline according to any one of claims 2-5, characterized in that, The fixed cavity (102) is provided with a mounting platform on the side away from the capacitor mounting cavity (101). The electronic control unit (3) is fixed on the mounting platform, and the capacitor outer tube lead (7) and capacitor inner tube lead (8) pass through the fixed cavity (102) and are connected to the electronic control unit (3).

7. A sensor for detecting ethanol content in gasoline according to claim 6, characterized in that, The other side of the electronic control unit (3) is also provided with a sealing cavity (103), which is also filled with potting compound (6); The sealing cavity (103) is also provided with a sealing cover (5) at the port, and the sealing cover (5) is detachably connected to the outer shell (1).

8. A sensor for detecting ethanol content in gasoline according to any one of claims 2-5, characterized in that, The outer casing (1) has an external socket (104) on one side, and a plug (4) is provided in the external socket (104), which is connected to the electronic control unit (3).

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