Combustion test device and test method for vehicle oxygen sensor

Abstract

The application relates to the technical field of oxygen sensor combustion testing, and particularly discloses a combustion testing device and a testing method for an oxygen sensor for vehicles. The application forms a closed annular energy storage cavity between the steady pressure testing pipe and the inner wall of the testing pipeline by coaxially arranging the steady pressure testing pipe with one end sealed in the testing pipeline, splits the traditional single-flow channel structure in series into two flow channel spaces, namely, an outer steady combustion flow channel and an inner pulse testing flow channel, which are independent and connected, can form a periodic pulse airflow completely matched with the real exhaust working condition of the automobile engine in the inner steady pressure testing pipe through the pulse generating mechanism, reproduce the real vehicle working environment of the oxygen sensor, and can absorb and block the reverse pressure wave generated by the pulse action from being transmitted to the upstream combustion end through the annular energy storage cavity, so that the deviation between the laboratory testing data and the real vehicle testing data is greatly reduced.

Description

Technical Field

[0001] This application relates to the field of oxygen sensor combustion testing technology, and in particular to a combustion testing device and method for automotive oxygen sensors. Background Technology

[0002] Automotive oxygen sensors are core sensing components installed in the exhaust system of automobile engines. They monitor the oxygen concentration in the exhaust in real time and feed back the air-fuel ratio signal to the engine's electronic control unit (ECU) to achieve closed-loop control of fuel injection. They are crucial for ensuring the purification efficiency of the three-way catalytic converter, controlling exhaust pollutant emissions, and reducing overall vehicle fuel consumption. They are widely used in the powertrain systems of traditional gasoline-powered vehicles and hybrid electric vehicles. The core performance characteristics of automotive oxygen sensors, such as response speed, measurement accuracy, linearity, and environmental adaptability, directly determine whether a vehicle can meet emission regulations. Therefore, throughout the entire process of oxygen sensor research and development, mass production quality inspection, and vehicle acceptance, it is essential to use a combustion testing device to simulate real engine exhaust conditions and accurately test all performance aspects. The combustion testing device is an indispensable core testing equipment in the automotive oxygen sensor industry.

[0003] Currently, the industry-standard automotive oxygen sensor combustion testing device is a horizontal coaxial series-connected single-channel steady-state structure. Along the airflow direction, it integrates combustion gas supply, operating condition adjustment, sensor testing, and exhaust gas aftertreatment units, along with an electrical control module to achieve closed-loop control and data acquisition. Its core working principle is as follows: High-temperature exhaust gas, similar to engine exhaust components, is generated through the combustion of oil and gas mixtures. After operating condition adjustment to the target test parameters, it is introduced into the test chamber to simultaneously flush both the standard reference oxygen sensor and the oxygen sensor under test. The core performance parameters of the oxygen sensor under test are calculated by the numerical difference and response time difference between the two signals.

[0004] However, the aforementioned device can only generate a steady-state continuous airflow, failing to replicate the periodic pulse exhaust conditions of a real vehicle engine. This results in significant discrepancies between laboratory test data and actual vehicle data, making the test results unreliable for practical vehicle applications. Even with the addition of a pulse generator valve, the generated reverse pressure wave directly interferes with upstream combustion stability. Adding a buffer structure to reduce this interference would cause severe pulse response lag, making it impossible to balance the accuracy of pulse condition reproduction with the stability of combustion conditions. Therefore, improvements to the aforementioned combustion testing equipment are urgently needed. Summary of the Invention

[0005] To address the technical problems of existing automotive oxygen sensor combustion testing devices being unable to accurately reproduce the pulse exhaust conditions of real vehicle engines, having significant deviations between test data and actual vehicle data, and being unable to balance the accuracy of pulse condition reproduction with the stability of combustion conditions, this application provides a combustion testing device and method for automotive oxygen sensors.

[0006] This application provides a combustion testing device for automotive oxygen sensors, employing the following technical solution: A combustion testing device for automotive oxygen sensors includes a test bench, within which a test pipe sealed at both ends is disposed. The test pipe contains, from one end to the other, the following components arranged sequentially: The combustion ignition mechanism is used to generate basic high-temperature exhaust gas that is consistent with the engine exhaust composition. The combustion state regulation mechanism is used to regulate the temperature, pressure, and air-fuel ratio of the high-temperature exhaust gas. A voltage-stabilizing energy storage mechanism is used to store exhaust gas under target operating conditions and block reverse fluctuations from interfering with front-end combustion. The energy storage space adjustment mechanism is used to adjust the size of the energy storage space of the exhaust gas under different test conditions. A pulse generator is used to generate a periodic pulsed airflow in the exhaust gas under target operating conditions, matching the actual exhaust conditions of a car engine.

[0007] Optionally, the combustion ignition mechanism includes an electromagnetic fuel injector, an air intake nozzle, and an electric spark plug arranged sequentially along the test pipe. The electromagnetic fuel injector is located at the end of the test pipe and extends into the test pipe. The air intake nozzle is installed on the side wall of the test pipe and its spray direction is set at an acute angle to the spray direction of the electromagnetic fuel injector. The electric spark plug is located inside the test pipe.

[0008] Optionally, a flame stabilizing plate is provided in the inner cavity of the test pipe away from the air inlet of the spark plug, and a plurality of air holes are evenly and spaced apart on the flame stabilizing plate.

[0009] Optionally, the combustion state adjustment mechanism includes a temperature sensor, a pressure sensor, an oxygen concentration monitoring sensor, and an air-fuel ratio analyzer. The test bench is equipped with a control system, and the temperature sensor, pressure sensor, oxygen concentration monitoring sensor, and air-fuel ratio analyzer are electrically connected to the control system.

[0010] Optionally, the voltage-stabilized energy storage mechanism includes a voltage-stabilized test tube and a voltage-stabilizing plate. One end of the voltage-stabilized test tube is sealed, and the other end extends out of the test pipe and is connected to the pulse generating mechanism. The voltage stabilizing test tube is coaxially disposed inside the test pipe and forms an annular energy storage cavity with the inner wall of the test pipe. Multiple flow ports are evenly and spaced along the circumferential direction on the outer wall of the voltage stabilizing test tube near the sealing end. The pressure stabilizing plate is disposed inside the test pipe and located outside the sealed end of the pressure stabilizing test tube. An opening is provided on the pressure stabilizing plate, which is directly opposite the sealed end of the pressure stabilizing test tube and has a cross-sectional area smaller than that of the sealed end of the pressure stabilizing test tube. The inner cavity of the voltage stabilization test tube is equipped with a standard oxygen sensor and an oxygen sensor to be tested. The standard oxygen sensor and the oxygen sensor to be tested are both located on the side of each of the flow ports away from the sealed end of the voltage stabilization test tube.

[0011] Optionally, the inlet of each of the flow ports faces the sealed end of the voltage-stabilizing test tube.

[0012] Optionally, the standard oxygen sensor and the oxygen sensor to be tested are arranged sequentially along the inner length of the voltage-stabilized test tube, and the vertical projection positions of the oxygen sensor to be tested and the standard oxygen sensor at the end of the voltage-stabilized test tube are different.

[0013] Optionally, the energy storage space adjustment mechanism includes a sealing plate, a threaded rod, a driving bevel gear, a driven bevel gear, and a drive motor. The sealing plate is slidably installed inside the test pipe and is fixedly connected to the pressure stabilizing plate through the threaded rod. The threaded rod is hollow and its inner cavity is connected to the space on the opposite side of the pressure stabilizing plate and the sealing plate. The ends of the threaded rod are rotatably connected to the pressure stabilizing plate and the sealing plate, respectively. The driven bevel gear is rotatably sleeved on the threaded rod and threadedly connected to the threaded rod. The driving bevel gear meshes with the driven bevel gear and is coaxially and fixedly connected to the output end of the drive motor. The drive motor is installed on the outer wall of the test pipe.

[0014] Optionally, the pulse generating mechanism includes a connecting pipe communicating with the end of the voltage stabilizing test tube and a high-speed switching valve disposed at the end of the connecting pipe, the high-speed switching valve being able to provide periodic pulse airflow matching the engine exhaust conditions.

[0015] This application also provides a combustion test method for an automotive oxygen sensor, employing one of the above-mentioned combustion test devices for an automotive oxygen sensor, and comprising the following steps: S1: Install the oxygen sensor to be tested and the standard oxygen sensor into the inner cavity of the pressure-stabilized test tube. According to the target engine test conditions corresponding to the oxygen sensor to be tested, drive the sealing plate and the pressure-stabilizing plate to slide along the test pipe axis through the energy storage space adjustment mechanism to adjust the effective volume of the annular energy storage cavity to a preset value that matches the target conditions. S2: Start the test device, spray atomized fuel into the test pipe through the electromagnetic fuel injector, and at the same time introduce combustion air through the air intake nozzle to form a homogeneous fuel-air mixture. The fuel-air mixture is ignited by the electric spark plug, and after being stabilized by the flame stabilizer plate, it generates basic high-temperature exhaust gas with the same composition as the engine exhaust. S3: Through the temperature sensor, pressure sensor, oxygen concentration monitoring sensor and air-fuel ratio analyzer of the combustion state adjustment mechanism, the operating parameters of the basic high-temperature exhaust gas are collected in real time and transmitted to the control system. The control system adjusts the temperature, pressure and air-fuel ratio of the exhaust gas to the target operating condition according to the preset target test parameters, and outputs the target operating condition exhaust gas in a steady state and uniform manner. S4: The exhaust gas under the target operating condition enters the annular energy storage cavity of the pressure stabilization and energy storage mechanism to complete pressure stabilization and storage, and then enters the inner cavity of the pressure stabilization and energy storage tube evenly through the flow port on the side wall of the pressure stabilization and energy storage tube. At the same time, the pulse generation mechanism is activated. Through the high-speed periodic on and off action of the high-speed switching valve, a periodic pulse airflow matching the actual exhaust condition of the target engine is formed in the inner cavity of the pressure stabilization and energy storage tube. The annular energy storage cavity synchronously blocks the reverse pressure wave generated by the pulse action, and prevents reverse fluctuations from interfering with the front combustion process. S5: The oxygen concentration signal of the pulsed airflow in the pressure-stabilized test tube is synchronously collected by the standard oxygen sensor and the oxygen sensor under test and transmitted to the control system. The control system compares and analyzes the two collected signals, calculates the core performance parameters of the oxygen sensor under test, and completes the test process. The exhaust gas after the test is purified by the three-way catalytic converter and reduced by the muffler before being discharged in compliance with regulations.

[0016] In summary, this application includes at least one of the following beneficial technical effects: 1. This application addresses the shortcomings of existing automotive oxygen sensor combustion testing devices, such as inherent distortion between steady-state test conditions and actual vehicle pulse exhaust conditions, and the inability to simultaneously achieve pulse condition reproduction and combustion stability. By coaxially installing a sealed pressure-stabilizing test tube within the test pipeline, a closed annular energy storage cavity is formed between the pressure-stabilizing test tube and the inner wall of the test pipeline. This splits the traditional series-connected single-channel structure into two independent yet interconnected flow channels: an outer steady-state combustion flow channel and an inner pulse test flow channel. This allows the pulse generation mechanism to generate a periodic pulse airflow within the inner pressure-stabilizing test tube that perfectly matches the actual exhaust conditions of an automotive engine, thus reproducing the actual vehicle working environment of the oxygen sensor. Furthermore, the annular energy storage cavity absorbs and blocks the reverse pressure wave generated by the pulse action from being transmitted upstream to the combustion end, significantly reducing the deviation between laboratory test data and actual vehicle data. This solves the pain point that existing steady-state testing devices cannot effectively guide actual vehicle applications.

[0017] 2. This application addresses the differentiated requirements for energy storage buffer space under different engine displacement and speed test conditions by designing an online stepless adjustable energy storage space adjustment mechanism. Through a drive motor and bevel gear meshing transmission, the threaded rod, sealing plate, and pressure stabilizing plate slide synchronously along the test pipeline axis. This allows for real-time adjustment of the effective axial length and volume of the annular energy storage cavity without disassembling or stopping the machine. For low-frequency idling conditions of small-displacement engines, the energy storage volume can be reduced to ensure pulse response speed. For high-frequency, high-speed conditions of large-displacement engines, the energy storage volume can be expanded to enhance the reverse wave blocking effect. This enables the test device to maintain optimal voltage stabilization and decoupling effects and pulse reproduction accuracy across the entire operating range, significantly expanding the applicable range of the test device. It can cover the full performance testing needs of oxygen sensors used in most fuel and hybrid vehicles on the market, improving the versatility and practicality of the device.

[0018] 3. This application achieves thorough and homogeneous mixing of combustion air and atomized fuel by using an electromagnetic fuel injector with an acute angled injection direction and an air intake nozzle. Combined with a flame stabilizing plate with uniformly spaced vents, it ensures stable flame fixation, preventing backfire, flameout, and combustion pulsation. This guarantees that the generated high-temperature exhaust gas composition is highly consistent with the actual exhaust gas composition of the engine. Furthermore, through a temperature sensor, pressure sensor, oxygen concentration monitoring sensor, and air-fuel ratio analyzer, along with a control system, it achieves real-time monitoring and fully automatic closed-loop adjustment of exhaust gas temperature, pressure, and air-fuel ratio. This allows for precise control of the gas source parameters within the target test range, significantly reducing the interference of gas source fluctuations on test results. It provides a stable, reliable, and controllable test gas source foundation for oxygen sensor performance testing.

[0019] 4. This application arranges the standard oxygen sensor and the oxygen sensor under test at intervals along the length of the inner cavity of the voltage-stabilized test tube, and the vertical projection positions of the two at the ends of the voltage-stabilized test tube are different. This can avoid airflow obstruction and mutual turbulence between the sensor probes, ensuring that each sensor is in a completely consistent test environment. This greatly improves the consistency and repeatability of the test results of oxygen sensors in the same batch, and can meet the batch and efficient testing requirements of the mass production quality inspection of oxygen sensors. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of the combustion test device in the embodiments of this application.

[0022] Figure 2 yes Figure 1 Partial cross-sectional view of the back of the combustion test device.

[0023] Figure 3 yes Figure 2 A schematic diagram of the structure at the linear guide rail and test pipe.

[0024] Figure 4 yes Figure 3 A schematic diagram of the structure at the linear guide rail.

[0025] Figure 5 yes Figure 3 A schematic diagram of the structure at the test pipeline.

[0026] Figure 6 yes Figure 5 A schematic diagram of the internal structure of the test pipeline from the front view.

[0027] Figure 7 yes Figure 6 A schematic diagram of the internal structure of the test pipeline from another perspective.

[0028] Figure label: 1. Test bench; 11. Test pipeline; 12. Flame stabilizer plate; 13. Annular energy storage cavity; 14. Flow port; 15. Standard oxygen sensor; 16. Oxygen sensor to be tested; 17. Three-way catalytic converter; 18. Muffler; 2. Combustion ignition mechanism; 21. Electromagnetic fuel injector; 22. Air intake nozzle; 23. Spark plug; 3. Combustion state regulation mechanism; 31. Temperature sensor; 32. Pressure sensor; 33. Oxygen concentration monitoring sensor; 34. Air-fuel ratio analyzer; 4. Voltage stabilizing energy storage mechanism; 41. Voltage stabilizing test tube; 42. Voltage stabilizing plate; 5. Energy storage space adjustment mechanism; 51. Sealing plate; 52. Threaded rod; 53. Driving bevel gear; 54. Driven bevel gear; 55. Drive motor; 6. Pulse generating mechanism; 61. Connecting pipe; 62. High-speed switching valve; 7. Linear guide rail; 71. Horizontal moving cylinder; 72. Lifting cylinder. Detailed Implementation

[0029] The following is in conjunction with the appendix Figure 1-7 This application will be described in further detail below.

[0030] This application discloses a combustion testing device for an automotive oxygen sensor.

[0031] Reference Figure 1 and Figure 2A combustion testing device for an automotive oxygen sensor includes a test bench 1. The test bench 1 has a test pipe 11 sealed at both ends. From one end to the other, the test pipe 11 is sequentially equipped with: a combustion ignition mechanism 2 for generating a basic high-temperature exhaust gas consistent with engine exhaust components; a combustion state adjustment mechanism 3 for adjusting the temperature, pressure, and air-fuel ratio of the high-temperature exhaust gas; a pressure-stabilizing energy storage mechanism 4 for storing target condition exhaust gas and blocking reverse fluctuations from interfering with front-end combustion; an energy storage space adjustment mechanism 5 for adjusting the size of the energy storage space for the target condition exhaust gas according to different test conditions; and a pulse generating mechanism 6 for generating a periodic pulse airflow of the target condition exhaust gas that matches the actual exhaust conditions of the automotive engine.

[0032] The combustion ignition mechanism 2 can generate basic high-temperature exhaust gas that is consistent with the engine exhaust composition, providing a matching gas source basis for oxygen sensor testing. The combustion state adjustment mechanism 3 can precisely adjust the temperature, pressure, and air-fuel ratio of the generated high-temperature exhaust gas to ensure that the operating parameters of the test gas source meet the target test requirements. The pressure stabilizing and energy storage mechanism 4 can store the adjusted target operating condition exhaust gas, while blocking the reverse fluctuations generated by downstream pulse action from interfering with the front-end combustion process, solving the industry pain point that the existing series structure cannot simultaneously achieve pulse simulation and combustion stability. The energy storage space adjustment mechanism 5 can adapt and adjust the size of the energy storage space of the exhaust gas under different engine test conditions to ensure the optimal pressure stabilization effect under different conditions. The pulse generation mechanism 6 can make the exhaust gas under the target condition form a periodic pulse airflow that matches the actual exhaust conditions of the car engine, so as to reproduce the actual working environment of the oxygen sensor in the vehicle as much as possible. Ultimately, it realizes the accurate performance test of the vehicle oxygen sensor under the actual engine pulse exhaust conditions, greatly reduces the deviation between laboratory test data and actual vehicle data, and solves the core problem of operating condition distortion of existing steady-state test devices.

[0033] Reference Figure 3 , Figure 4 and Figure 5 The combustion ignition mechanism 2 includes an electromagnetic fuel injector 21, an air intake nozzle 22, and an electric spark plug 23 arranged sequentially along the test pipe 11. The electromagnetic fuel injector 21 is located at the end of the test pipe 11 and extends into the test pipe 11. The air intake nozzle 22 is installed on the side wall of the test pipe 11 and its spray direction is set at an acute angle to the spray direction of the electromagnetic fuel injector 21. The electric spark plug 23 is located inside the test pipe 11.

[0034] When it is necessary to generate basic high-temperature exhaust gas with the same composition as the engine exhaust, the electromagnetic fuel injector 21, which is set at the end of the test pipe 11 and extends into the test pipe 11, precisely injects atomized fuel into the test pipe 11. At the same time, combustion air is introduced through the air intake nozzle 22 installed on the side wall of the test pipe 11. The injection direction of the air intake nozzle 22 is set at an acute angle with the injection direction of the electromagnetic fuel injector 21, which allows the combustion air and atomized fuel to fully collide and mix during the injection process, forming a homogeneous fuel-air mixture. Then, the homogeneous fuel-air mixture is reliably ignited by the electric spark plug 23 set in the test pipe 11. Finally, the fuel-air mixture is fully and uniformly mixed and stably ignited, ensuring that the composition of the generated basic high-temperature exhaust gas is highly consistent with the actual exhaust composition of the engine. This avoids problems such as incomplete combustion and exhaust gas composition fluctuations caused by uneven fuel-air mixing, and provides a stable and reliable air source foundation for subsequent operating condition adjustment and performance testing.

[0035] Reference Figure 6 and Figure 7 A flame stabilizing plate 12 is installed inside the test pipe 11, away from the air intake nozzle 22, with multiple air holes evenly spaced on the flame stabilizing plate 12. These air holes on the flame stabilizing plate 12 can fix and limit the combustion flame after ignition, while ensuring uniform flow of combustion air. This eliminates airflow pulsation and flame shaking during combustion, preventing combustion interruption caused by high-speed airflow extinguishing the flame. Ultimately, this achieves continuous and stable operation of the combustion process, significantly reducing fluctuations in combustion conditions and ensuring constant and controllable operating parameters of the output high-temperature exhaust gas, providing a stable combustion foundation for subsequent precise adjustment of operating conditions.

[0036] Reference Figure 5 , Figure 6 and Figure 7 The combustion state adjustment mechanism 3 includes a temperature sensor 31, a pressure sensor 32, an oxygen concentration monitoring sensor 33, and an air-fuel ratio analyzer 34. The test bench 1 is equipped with a control system. The temperature sensor 31, pressure sensor 32, oxygen concentration monitoring sensor 33, and air-fuel ratio analyzer 34 are electrically connected to the control system.

[0037] Through temperature sensor 31, pressure sensor 32, oxygen concentration monitoring sensor 33, and air-fuel ratio analyzer 34, the temperature, pressure, oxygen concentration, and air-fuel ratio of the high-temperature exhaust gas in the test pipeline 11 can be collected in real time. The collected parameters are transmitted to the control system set in the test bench 1 in real time. The control system can compare the collected real-time parameters with the preset target test parameters and adjust the front-end combustion parameters accordingly based on the comparison results. In the end, real-time monitoring and fully automatic closed-loop adjustment of the high-temperature exhaust gas operating parameters are realized, ensuring that the temperature, pressure, and air-fuel ratio of the exhaust gas can be accurately and stably maintained within the target test parameter range. This greatly improves the operating condition control accuracy of the test gas source and avoids the problem of oxygen sensor test data distortion caused by fluctuations in gas source parameters.

[0038] Reference Figure 5 , Figure 6 and Figure 7 The voltage stabilizing energy storage mechanism 4 includes a voltage stabilizing test tube 41 and a voltage stabilizing plate 42. One end of the voltage stabilizing test tube 41 is sealed, and the other end extends out of the test pipe 11 and is connected to the pulse generating mechanism 6.

[0039] The pressure stabilizing test tube 41 is coaxially arranged inside the test pipe 11, and forms an annular energy storage cavity 13 between it and the inner wall of the test pipe 11. Multiple flow ports 14 are evenly spaced along the circumference on the outer wall of the pressure stabilizing test tube 41 near the sealing end.

[0040] The pressure stabilizing plate 42 is disposed inside the test pipe 11 and located outside the sealing end of the pressure stabilizing test tube 41. The pressure stabilizing plate 42 has an opening that faces the sealing end of the pressure stabilizing test tube 41 and has a cross-sectional area smaller than that of the sealing end of the pressure stabilizing test tube 41.

[0041] The inner cavity of the voltage stabilizing test tube 41 is equipped with a standard oxygen sensor 15 and an oxygen sensor to be tested 16. The standard oxygen sensor 15 and the oxygen sensor to be tested 16 are located on the side of each flow port 14 away from the sealed end of the voltage stabilizing test tube 41.

[0042] The annular energy storage cavity 13 can stably store the target operating condition exhaust gas after front-end adjustment, providing a constant pressure gas source for oxygen sensor testing. Multiple flow ports 14 can uniformly introduce the stable exhaust gas in the annular energy storage cavity 13 into the inner cavity of the pressure stabilizing test tube 41. The opening of the pressure stabilizing plate 42 is directly opposite the sealed end of the pressure stabilizing test tube 41, which can rectify and buffer the airflow entering the annular energy storage cavity 13, further eliminating airflow pulsation.

[0043] The annular energy storage cavity 13 can block the reverse pressure wave generated by the pulse action from being transmitted to the upstream combustion end. The standard oxygen sensor 15 and the oxygen sensor under test 16 can complete synchronous signal acquisition in a stable pulse airflow environment, thus achieving complete physical decoupling between the steady-state combustion process and the pulse test process. This not only reproduces the real pulse exhaust conditions of the engine, but also minimizes the interference of reverse fluctuations on the front-end combustion stability. At the same time, it ensures that the standard oxygen sensor 15 and the oxygen sensor under test 16 are in a completely consistent test environment, which greatly improves the accuracy and data reliability of oxygen sensor performance testing.

[0044] Furthermore, refer to Figure 6 The inlet of each flow port 14 faces the sealed end of the voltage stabilizing test tube 41.

[0045] By positioning the inlets of each flow port 14 toward the sealed end of the pressure-stabilizing test tube 41, the air intake direction of the flow port 14 can be counteracted by the propagation direction of the axial reverse pressure wave generated by the downstream pulse action. When the reverse pressure wave passes through the flow port 14, it will be directly blocked and canceled by the air intake airflow, making it difficult to enter the annular energy storage cavity 13. This further blocks and eliminates the reverse pressure wave, greatly enhances the decoupling and pressure stabilizing effect of the annular energy storage cavity 13, and completely eliminates the interference of reverse fluctuations on the front-end combustion conditions. At the same time, it can make the airflow entering the inner cavity of the pressure-stabilizing test tube 41 form a uniform swirling flow, eliminate the problem of airflow thermal stratification and flow deviation in the test tube, and ensure the uniformity of the flow field of the standard oxygen sensor 15 and the oxygen sensor under test 16.

[0046] The standard oxygen sensor 15 and the oxygen sensor to be tested 16 are arranged alternately along the inner length of the voltage-stabilized test tube 41, and the vertical projection positions of the oxygen sensor to be tested 16 and the standard oxygen sensor 15 at the end of the voltage-stabilized test tube 41 are different.

[0047] When it is necessary to ensure the consistency of synchronous testing of multiple oxygen sensors and avoid mutual turbulence between sensors affecting the test accuracy, the standard oxygen sensor 15 and the oxygen sensor to be tested 16 are arranged at intervals along the inner length of the voltage stabilizing test tube 41. This allows each oxygen sensor to be tested 16 to be in an independent airflow section, avoiding airflow obstruction and turbulence between the front and rear sensors. Meanwhile, the vertical projection positions of the oxygen sensor under test 16 and the standard oxygen sensor 15 at the end of the voltage-stabilized test tube 41 are different, which allows the standard oxygen sensor 15 and the oxygen sensor under test 16 to be staggered in the circumferential direction of the voltage-stabilized test tube 41, further eliminating mutual airflow interference between sensor probes. Ultimately, this enables the synchronous testing of multiple sets of oxygen sensors under test 16 and standard oxygen sensors 15 in a uniform flow field, ensuring that each sensor is in a completely consistent test environment. This significantly improves the consistency and repeatability of test results for oxygen sensors in the same batch, meeting the batch testing requirements of mass production quality inspection.

[0048] Reference Figure 5 , Figure 6 and Figure 7 The energy storage space adjustment mechanism 5 includes a sealing plate 51, a threaded rod 52, a driving bevel gear 53, a driven bevel gear 54, and a drive motor 55. The sealing plate 51 is slidably installed in the test pipe 11 and is fixedly connected to the pressure stabilizing plate 42 through the threaded rod 52. The threaded rod 52 is hollow and its inner cavity is connected to the space on the opposite side of the pressure stabilizing plate 42 and the sealing plate 51. The ends of the threaded rod 52 are rotatably connected to the pressure stabilizing plate 42 and the sealing plate 51, respectively.

[0049] The driven bevel gear 54 is rotatably sleeved on the threaded rod 52 and threadedly connected to the threaded rod 52. The driving bevel gear 53 meshes with the driven bevel gear 54 and is coaxially fixedly connected to the output end of the drive motor 55. The drive motor 55 is installed on the outer wall of the test pipe 11.

[0050] When it is necessary to adjust the size of the energy storage space of the exhaust gas under the target working condition according to different test conditions, the drive motor 55 installed on the outer wall of the test pipeline 11 provides power. The drive motor 55 drives the active bevel gear 53, which is coaxially fixedly connected to its output end, to rotate. The active bevel gear 53 drives the driven bevel gear 54 to rotate synchronously through meshing transmission. The driven bevel gear 54 is rotated and sleeved on the threaded rod 52 and threadedly connected to the threaded rod 52, which can convert the rotational motion into the axial linear motion of the threaded rod 52.

[0051] The threaded rod 52 drives the sealing plate 51 and the pressure stabilizing plate 42, which are fixedly connected to it, to slide synchronously along the axial direction of the test pipeline 11, thereby changing the axial length of the annular energy storage cavity 13 and realizing stepless adjustment of the energy storage space size. The threaded rod 52 is hollow and its inner cavity is connected to the space on the opposite side of the pressure stabilizing plate 42 and the sealing plate 51, which can ensure the pressure balance on both sides of the sealing plate 51 and avoid the pressure difference from hindering the sliding adjustment of the sealing plate 51. Meanwhile, the ends of the threaded rod 52 are rotatably connected to the pressure stabilizing plate 42 and the sealing plate 51 respectively, which can ensure the stability of the transmission process of the threaded rod 52. Ultimately, the volume of the annular energy storage cavity 13 can be adjusted online steplessly. According to the test conditions of engines with different displacements and speeds, the energy storage space can be adjusted to the optimal volume, ensuring the best voltage stabilization and decoupling effect and pulse response accuracy in the entire operating range. This greatly expands the applicable range of the test device. At the same time, the adjustment process does not require disassembly or shutdown, making the operation convenient and efficient, and improving the ease of use and testing efficiency of the test device.

[0052] Reference Figure 5 , Figure 6 and Figure 7The pulse generating mechanism 6 includes a connecting pipe 61 connected to the end of the voltage stabilizing test pipe 41 and a high-speed switching valve 62 disposed at the end of the connecting pipe 61. The high-speed switching valve 62 can provide periodic pulse airflow that matches the engine exhaust conditions.

[0053] When it is necessary to make the exhaust gas under the target operating condition form a periodic pulse airflow that matches the actual exhaust operating condition of a car engine, the inner cavity of the pressure stabilizing test tube 41 is sealed and connected to the high-speed switching valve 62 through the connecting pipe 61 connected to the end of the pressure stabilizing test tube 41. The high-speed switching valve 62 can control the airflow rhythm in the inner cavity of the pressure stabilizing test tube 41 through high-speed periodic on and off actions, thereby forming a periodic pulse airflow in the inner cavity of the pressure stabilizing test tube 41 that perfectly matches the frequency and duty cycle of the target engine exhaust operating condition. Ultimately, the actual exhaust pulse operating condition of the car engine is reproduced, enabling the oxygen sensor 16 under test to complete performance testing in a working environment that is completely consistent with the actual vehicle installation. This significantly reduces the deviation between laboratory test data and actual vehicle installation data, solving the core industry pain point of the inherent distortion of the operating condition of existing steady-state test devices.

[0054] The test bench 1 is also equipped with a three-way catalytic converter 17 and a muffler 18. The three-way catalytic converter 17 is connected to the outlet of the high-speed switching valve 62, and the muffler 18 is connected to the outlet of the three-way catalytic converter 17.

[0055] The gas discharged from the high-speed switching valve 62 is purified by the three-way catalytic converter 17 and silenced by the muffler 18, so that the final discharged gas meets the environmental protection requirements.

[0056] Furthermore, refer to Figure 3 and Figure 4 To enable rapid measurement of the sensor under test, a linear guide rail 7 is installed on the test bench 1. The length of the linear guide rail 7 is consistent with the length direction of the test pipe 11. A horizontal moving cylinder 71 is installed on the moving part of the linear guide rail 7. The horizontal moving cylinder 71 can extend and retract along the moving direction perpendicular to the linear guide rail 7. The first oxygen sensor 16 to be tested is fixed on the extension end of the horizontal moving cylinder 71. A lifting cylinder 72 is provided on the extension end of the horizontal moving cylinder 71. The lifting cylinder 72 is installed on the extension end of the horizontal moving cylinder 71 and can be raised and lowered along the moving direction perpendicular to the horizontal moving cylinder 71. The second oxygen sensor 16 to be tested is provided on the lifting end of the lifting cylinder 72.

[0057] The first and second oxygen sensors 16 to be tested are fixed in their respective positions. The fixing method can be clamping or fixing with a fastener.

[0058] The implementation principle of the combustion test device for automotive oxygen sensor in this application embodiment is as follows: when it is necessary to test the combustion performance of automotive oxygen sensor, one or more oxygen sensors to be tested are fixed at the corresponding positions of horizontal moving cylinder 71 and lifting cylinder 72. According to the target engine test conditions corresponding to the oxygen sensor 16 to be tested, the effective volume of the annular energy storage cavity 13 is adjusted to a preset value that matches the target conditions through the energy storage space adjustment mechanism 5 to complete the pre-test preparation work. The test device is then started, and atomized fuel is injected into the test pipe 11 through the electromagnetic fuel injector 21. At the same time, combustion air is introduced through the air intake nozzle 22 to form a homogeneous fuel-air mixture. The fuel-air mixture is ignited by the electric spark plug 23 and then stabilized by the flame stabilizer plate 12 to generate basic high-temperature exhaust gas with the same exhaust composition as the engine. Then, through the temperature sensor 31, pressure sensor 32, oxygen concentration monitoring sensor 33 and air-fuel ratio analyzer 34 of the combustion state adjustment mechanism 3, all the operating parameters of the high-temperature exhaust gas are collected in real time and transmitted to the control system. The control system adjusts the temperature, pressure and air-fuel ratio of the exhaust gas to the target operating condition according to the preset target test parameters, and outputs the target operating condition exhaust gas in a closed loop. After the exhaust gas under the target operating condition enters the annular energy storage cavity 13 of the pressure stabilizing energy storage mechanism 4 and completes pressure stabilization and storage, it is evenly introduced into the inner cavity of the pressure stabilizing test tube 41 through the flow port 14 on the side wall of the pressure stabilizing test tube 41. At the same time, the high-speed switching valve 62 of the pulse generating mechanism 6 is activated. Through high-speed periodic on and off action, a periodic pulse airflow matching the actual exhaust condition of the target engine is formed in the inner cavity of the pressure stabilizing test tube 41. The annular energy storage cavity 13 synchronously blocks the reverse pressure wave generated by the pulse action, and prevents the reverse fluctuation from interfering with the front combustion process. Finally, the oxygen concentration signal of the pulsed airflow in the pressure-stabilized test tube 41 is synchronously collected by the standard oxygen sensor 15 and the oxygen sensor under test 16 and transmitted to the control system. The control system compares and analyzes the two collected signals, calculates the core performance parameters of the oxygen sensor under test 16, and completes the test process. The exhaust gas after the test is purified by the three-way catalytic converter 17 and reduced by the muffler 18 before being discharged in compliance with regulations.

[0059] This application also discloses a combustion test method for an automotive oxygen sensor, employing one of the above-described combustion test devices for an automotive oxygen sensor, and comprising the following steps: S1: Install the oxygen sensor to be tested 16 and the standard oxygen sensor 15 into the inner cavity of the pressure-stabilized test tube 41. According to the target engine test conditions corresponding to the oxygen sensor to be tested 16, drive the sealing plate 51 and the pressure-stabilizing plate 42 to slide along the test pipe 11 axially through the energy storage space adjustment mechanism 5 to adjust the effective volume of the annular energy storage cavity 13 to a preset value that matches the target conditions. S2: Start the test device, spray atomized fuel into the test pipe 11 through the electromagnetic fuel injector 21, and at the same time introduce combustion air through the air intake nozzle 22 to form a homogeneous fuel-air mixture. The fuel-air mixture is ignited by the electric spark plug 23 and stabilized by the flame stabilizer plate 12 to generate basic high-temperature exhaust gas with the same composition as the engine exhaust. S3: The temperature sensor 31, pressure sensor 32, oxygen concentration monitoring sensor 33 and air-fuel ratio analyzer 34 of the combustion state adjustment mechanism 3 collect the operating parameters of the basic high temperature exhaust gas in real time and transmit them to the control system. The control system adjusts the temperature, pressure and air-fuel ratio of the exhaust gas to the target operating condition according to the preset target test parameters in a closed loop and outputs a steady and uniform target operating condition exhaust gas. S4: The exhaust gas under the target operating condition enters the annular energy storage cavity 13 of the pressure stabilizing energy storage mechanism 4 to complete pressure stabilization and storage, and then enters the inner cavity of the pressure stabilizing test tube 41 evenly through the flow port 14 on the side wall of the pressure stabilizing test tube 41. At the same time, the pulse generating mechanism 6 is activated. Through the high-speed periodic on and off action of the high-speed switching valve 62, a periodic pulse airflow matching the actual exhaust condition of the target engine is formed in the inner cavity of the pressure stabilizing test tube 41. The annular energy storage cavity 13 synchronously blocks the reverse pressure wave generated by the pulse action to prevent reverse fluctuation from interfering with the front combustion process. S5: The oxygen concentration signal of the pulsed airflow in the pressure-stabilized test tube 41 is synchronously collected by the standard oxygen sensor 15 and the oxygen sensor under test 16 and transmitted to the control system. The control system compares and analyzes the two collected signals, calculates the core performance parameters of the oxygen sensor under test 16, and completes the test process. The exhaust gas after the test is purified by the three-way catalytic converter 17 and the noise is reduced by the muffler 18 before being discharged in compliance with regulations.

[0060] The above are all optional embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A combustion testing device for an automotive oxygen sensor, characterized in that: Includes a test bench (1), wherein a test pipe (11) sealed at both ends is provided inside the test bench (1), and the test pipe (11) is provided with the following components sequentially from one end to the other: Combustion ignition mechanism (2) is used to generate basic high-temperature exhaust gas that is consistent with the engine exhaust composition; Combustion state adjustment mechanism (3) is used to adjust the temperature, pressure and air-fuel ratio of high-temperature exhaust gas; The pressure-stabilizing energy storage mechanism (4) is used to store the exhaust gas under the target operating condition and block the reverse fluctuation from interfering with the front-end combustion. The energy storage space adjustment mechanism (5) is used to adjust the size of the energy storage space of the exhaust gas under the target working condition according to different test conditions. The pulse generating mechanism (6) is used to generate a periodic pulse airflow that matches the actual exhaust conditions of the automobile engine.

2. The combustion testing device for an automotive oxygen sensor according to claim 1, characterized in that: The combustion ignition mechanism (2) includes an electromagnetic fuel injector (21), an air intake nozzle (22), and an electric spark plug (23) arranged sequentially along the test pipe (11). The electromagnetic fuel injector (21) is located at the end of the test pipe (11) and extends into the test pipe (11). The air intake nozzle (22) is installed on the side wall of the test pipe (11) and its spray direction is set at an acute angle to the spray direction of the electromagnetic fuel injector (21). The electric spark plug (23) is located inside the test pipe (11).

3. The combustion testing device for an automotive oxygen sensor according to claim 2, characterized in that: A flame stabilizing plate (12) is provided in the inner cavity of the test pipe (11) away from the air inlet (22) of the electric spark plug (23), and a plurality of air holes are evenly and spaced apart on the flame stabilizing plate (12).

4. The combustion testing device for an automotive oxygen sensor according to claim 1, characterized in that: The combustion state adjustment mechanism (3) includes a temperature sensor (31), a pressure sensor (32), an oxygen concentration monitoring sensor (33), and an air-fuel ratio analyzer (34). The test bench (1) is equipped with a control system. The temperature sensor (31), pressure sensor (32), oxygen concentration monitoring sensor (33), and air-fuel ratio analyzer (34) are electrically connected to the control system.

5. The combustion testing device for an automotive oxygen sensor according to claim 1, characterized in that: The voltage stabilizing energy storage mechanism (4) includes a voltage stabilizing test tube (41) and a voltage stabilizing plate (42). One end of the voltage stabilizing test tube (41) is sealed, and the other end extends out of the test pipe (11) and is connected to the pulse generating mechanism (6). The voltage stabilizing test tube (41) is coaxially disposed inside the test pipe (11) and forms an annular energy storage cavity (13) between it and the inner wall of the test pipe (11). Multiple flow ports (14) are evenly and spaced along the circumference on the outer wall of the voltage stabilizing test tube (41) near the sealing end. The pressure stabilizing plate (42) is disposed inside the test pipe (11) and located outside the sealing end of the pressure stabilizing test tube (41). An opening is provided on the pressure stabilizing plate (42), which is directly opposite the sealing end of the pressure stabilizing test tube (41) and has a cross-sectional area smaller than the cross-sectional area of ​​the sealing end of the pressure stabilizing test tube (41). The inner cavity of the voltage stabilizing test tube (41) is equipped with a standard oxygen sensor (15) and an oxygen sensor to be tested (16). The standard oxygen sensor (15) and the oxygen sensor to be tested (16) are located on the side of each of the flow ports (14) away from the sealed end of the voltage stabilizing test tube (41).

6. The combustion testing device for an automotive oxygen sensor according to claim 5, characterized in that: The inlet of each of the flow ports (14) faces the sealed end of the voltage stabilizing test tube (41).

7. The combustion testing device for an automotive oxygen sensor according to claim 5, characterized in that: The standard oxygen sensor (15) and the oxygen sensor to be tested (16) are arranged at intervals along the inner length of the voltage-stabilized test tube (41), and the vertical projection positions of the oxygen sensor to be tested (16) and the standard oxygen sensor (15) at the end of the voltage-stabilized test tube (41) are different.

8. The combustion testing device for an automotive oxygen sensor according to claim 1, characterized in that: The energy storage space adjustment mechanism (5) includes a sealing plate (51), a threaded rod (52), an active bevel gear (53), a driven bevel gear (54), and a drive motor (55). The sealing plate (51) is slidably installed in the test pipe (11) and is fixedly connected to the pressure stabilizing plate (42) through the threaded rod (52). The threaded rod (52) is hollow and its inner cavity is connected to the space on the side away from the pressure stabilizing plate (42) and the sealing plate (51), respectively. The ends of the threaded rod (52) are rotatably connected to the pressure stabilizing plate (42) and the sealing plate (51), respectively. The driven bevel gear (54) is rotatably sleeved on the threaded rod (52) and threadedly connected to the threaded rod (52). The driving bevel gear (53) meshes with the driven bevel gear (54) and is coaxially fixedly connected to the output end of the drive motor (55). The drive motor (55) is installed on the outer wall of the test pipe (11).

9. A combustion testing device for an automotive oxygen sensor according to claim 1, characterized in that: The pulse generating mechanism (6) includes a connecting pipe (61) connected to the end of the voltage stabilizing test tube (41) and a high-speed switching valve (62) disposed at the end of the connecting pipe (61). The high-speed switching valve (62) is capable of providing periodic pulse airflow that matches the engine exhaust conditions.

10. A combustion test method for an automotive oxygen sensor, employing a combustion test apparatus for an automotive oxygen sensor as described in any one of claims 1-9, characterized in that: The following steps are adopted: S1: Install the oxygen sensor to be tested (16) and the standard oxygen sensor (15) into the inner cavity of the pressure-stabilized test tube (41). According to the target engine test conditions corresponding to the oxygen sensor to be tested (16), drive the sealing plate (51) and the pressure-stabilizing plate (42) to slide along the test pipe (11) axially through the energy storage space adjustment mechanism (5) to adjust the effective volume of the annular energy storage cavity (13) to a preset value that matches the target conditions. S2: Start the test device and spray atomized fuel into the test pipe (11) through the electromagnetic fuel injector (21). At the same time, combustion air is introduced through the air intake nozzle (22) to form a homogeneous fuel-air mixture. The fuel-air mixture is ignited by the electric spark plug (23). After being stabilized by the flame stabilizer plate (12), it generates basic high-temperature exhaust gas that is consistent with the engine exhaust components. S3: The temperature sensor (31), pressure sensor (32), oxygen concentration monitoring sensor (33) and air-fuel ratio analyzer (34) of the combustion state adjustment mechanism (3) collect the working parameters of the basic high temperature exhaust gas in real time and transmit them to the control system. The control system adjusts the temperature, pressure and air-fuel ratio of the exhaust gas to the target working condition according to the preset target test parameters in a closed loop and outputs the target working condition exhaust gas in a steady and uniform state. S4: The exhaust gas under the target operating condition enters the annular energy storage cavity (13) of the pressure stabilization and energy storage mechanism (4) to complete pressure stabilization and storage, and then enters the inner cavity of the pressure stabilization test tube (41) evenly through the flow port (14) on the side wall of the pressure stabilization test tube (41). At the same time, the pulse generation mechanism (6) is activated. Through the high-speed periodic on and off action of the high-speed switching valve (62), a periodic pulse airflow matching the actual exhaust condition of the target engine is formed in the inner cavity of the pressure stabilization test tube (41). The annular energy storage cavity (13) synchronously blocks the reverse pressure wave generated by the pulse action, and prevents the reverse fluctuation from interfering with the front combustion process. S5: The oxygen concentration signal of the pulse airflow in the pressure-stabilized test tube (41) is synchronously collected by the standard oxygen sensor (15) and the oxygen sensor under test (16) and transmitted to the control system. The control system compares and analyzes the two collected signals, calculates the core performance parameters of the oxygen sensor under test (16), and completes the test process. The exhaust gas after the test is purified by the three-way catalytic converter (17) and reduced by the muffler (18) before being discharged in compliance with regulations.

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