Method and device for detecting resistance of surface oxide conductor

Abstract

The application discloses a kind of surface oxide layer conductor resistance detection method and device, and the same constant DC high voltage source is used to complete oxide film breakdown and resistance measurement synchronously, and breakdown process and measurement process are completely overlapped in time, without equipment switching gap;The beneficial effects of the present application are: the above-mentioned method discards the inherent mode of low-voltage measurement of multimeter, and 500V-1500V constant DC high voltage is directly applied to the conductor to be measured, and the high-voltage electric field is used to break through the surface oxide insulation film in 10ms, to form a stable conductive channel directly to the conductor body, which fundamentally solves the industry problem that the low-voltage of multimeter cannot penetrate the oxide film and the measurement value deviates seriously from the true body resistance.

Description

Technical Field

[0001] This invention relates to a method and apparatus for detecting the resistance of a conductive surface oxide layer. Background Technology

[0002] In the production, quality inspection, and maintenance of electrical equipment and electronic components, resistance is a core indicator for measuring conductivity and contact reliability. However, most metallic conductors, such as spark plugs, relay contacts, high-voltage switch contacts, and cable joints, naturally develop a thin and dense oxide insulating film on their surface during production, storage, or use.

[0003] In the existing technology, the industry generally uses multimeters or DC bridges for resistance measurement, but their output voltage is only 1.5V to 9V, which cannot penetrate the above-mentioned oxide insulating film. The measured value is actually the series value of the oxide film insulation resistance plus the conductor body resistance, and the measurement error can reach 30% to 80%, which can easily lead to the misjudgment and scrapping of qualified products. In view of this, the present invention proposes a resistance detection method and device for surface oxide layer conductors to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a method and apparatus for detecting the resistance of a conductive surface oxide layer, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for detecting the resistance of a conductive surface oxide layer is characterized by: using the same constant DC high-voltage source to simultaneously complete oxide film breakdown and resistance measurement, with the breakdown process and measurement process completely overlapping in time and without equipment switching gaps, specifically including the following steps:

[0007] S1: Connect the two conductive detection terminals of the conductor to be tested directly to the output circuit of the constant voltage DC power supply. The output circuit contains only a high-precision current measurement unit connected in series, without a high-voltage or low-voltage switching circuit.

[0008] S2: Apply a constant DC high voltage of 500V to 1500V to both ends of the conductor under test at one time. During the entire detection cycle, before the oxide insulating film breaks down, during the breakdown process, and after the current stabilizes, the output voltage of the constant DC high voltage remains constant.

[0009] S3: The oxide insulating film on the surface of the conductor under test is broken down within 10ms under the action of the constant DC high voltage electric field, forming a stable conductive channel;

[0010] S4: The high-precision current measurement unit starts to collect the loop current in real time at the same time as the oxide film breaks down, and reads the stable current value after the current stabilizes.

[0011] S5: The microprocessor directly calculates the actual resistance value of the conductor under test according to Ohm's law R=U / I, where U is the constant DC high voltage output value throughout the process;

[0012] S6: Compare the calculated actual resistance value with the preset standard range and automatically output the pass or fail judgment result.

[0013] As an improvement to the above technical solution, the preferred output voltage of the constant DC high voltage is 1000V, the output ripple coefficient is ≤0.5%, and the voltage calibration accuracy is stable within ±0.1%; the measurement range of the high-precision current measurement unit is 0.1mA~1A, the measurement accuracy is ±0.1%, and the response time is ≤1ms.

[0014] The breakdown time of the oxide insulating film is <10ms, the current stabilization time is ≤100ms, the total time for a single-channel complete test is ≤200ms, completely eliminating the influence of the secondary oxide film generated during equipment switching gaps on the measurement results, and the measurement deviation is ≤2.5%.

[0015] As an improvement to the above technical solution, for dense conductors under test with an oxide film thickness greater than 5 μm, an adaptive step-by-step voltage boost detection mode is adopted. Step S2 is specifically as follows:

[0016] S21: The DC voltage applied across the conductor under test is gradually increased at a linear rate of 100V / s.

[0017] S22: Real-time monitoring of the circuit current change rate. When the current change rate exceeds the preset threshold, it is determined that the oxide insulation film has been broken down.

[0018] S23: Immediately lock the output voltage to 1000V and keep it constant, then proceed to step S3.

[0019] As an improvement to the above technical solution, a multi-channel parallel independent detection architecture is adopted, with N detection channels N≥2, which simultaneously detects N conductors to be tested. Each channel is equipped with an independent constant voltage DC power supply subunit and a high-precision current measurement subunit, and the detection process of each channel does not interfere with each other.

[0020] When there are 8 detection channels, the total detection time is ≤300ms when the 8 channels are detected in parallel, and a batch detection of no less than 12,000 conductors to be tested can be completed per hour.

[0021] As an improvement to the above technical solution, the adjustable output characteristics of the same constant voltage DC power supply are utilized to integrate insulation resistance detection and power frequency withstand voltage detection functions on the same device.

[0022] The insulation resistance detection step is as follows: apply a preset constant DC high voltage to the conductor to be tested, measure the leakage current of the circuit and calculate the insulation resistance value;

[0023] The withstand voltage test procedure is as follows: apply a preset constant high voltage to the conductor under test and maintain it for a specified time, and monitor whether the circuit current changes abruptly to determine whether the withstand voltage is qualified.

[0024] As an improvement to the above technical solution, the conductor to be tested is an electrical component whose surface is prone to forming an oxide insulating film, including but not limited to spark plugs, relay contacts, high-voltage switch contacts, wiring terminals, and cable connectors.

[0025] A resistance detection device for a surface oxide layer conductive material, employing a single constant voltage DC power supply module to simultaneously achieve oxide film breakdown and resistance measurement, specifically including:

[0026] The constant voltage DC power supply module is used to output a constant DC high voltage of 500V to 1500V throughout the entire detection cycle, and the output voltage remains unchanged throughout the entire detection cycle.

[0027] A high-precision current measurement module is directly connected in series in the output circuit of the constant voltage DC power supply module to collect the circuit current in real time while the oxide film breaks down.

[0028] The real-time voltage calibration module is electrically connected to the constant voltage DC power supply module and is used to dynamically calibrate the output voltage to ensure that the voltage accuracy is stable within ±0.1%.

[0029] The microprocessor control module is electrically connected to each of the above modules and is used to control the detection process, calculate the actual resistance value of the body according to Ohm's law, and output the judgment result.

[0030] A multi-safety protection module is connected in parallel with the output circuit, integrating overcurrent protection, overvoltage protection, short circuit protection, and automatic discharge function after detection;

[0031] The display and operation module is electrically connected to the microprocessor control module and is used to display measurement data and judgment results, and provide a parameter setting interface.

[0032] As an improvement to the above technical solution, the preferred output voltage of the constant voltage DC power supply module is 1000V, and the output ripple coefficient is ≤0.5%; the measurement range of the high-precision current measurement module is 0.1mA~1A, the measurement accuracy is ±0.1%, and the response time is ≤1ms.

[0033] The automatic discharge function of the multiple safety protection module is as follows: immediately after the detection is completed, the parallel discharge circuit is triggered to discharge the energy storage capacitor in the output circuit. The discharge time is ≤1s. After the discharge is completed, a safety prompt signal is automatically output.

[0034] As an improvement to the above technical solution, the detection device also includes a data storage and communication module, which is electrically connected to the microprocessor control module, for storing all detection data and supporting USB data export, RS485 industrial bus communication and 4G / 5G IoT remote communication.

[0035] The detection device also includes an automatic feeding mechanism and an automatic sorting mechanism, both of which are electrically connected to the microprocessor control module, enabling fully unmanned operation of the entire process of automatic feeding, automatic detection, automatic sorting, and automatic data uploading of the conductive material to be tested.

[0036] As an improvement to the above technical solution, the detection device is a multi-channel batch detection device, which includes N independent detection channels N≥2. Each detection channel is equipped with an independent constant voltage DC power supply submodule, a high-precision current measurement submodule and a safety protection submodule. All detection channels are uniformly scheduled by the same microprocessor control module.

[0037] Compared with the prior art, the beneficial effects of the present invention are:

[0038] The above method abandons the inherent mode of low-voltage measurement of multimeters. It uses a constant DC high voltage of 500V to 1500V to directly act on the conductor under test. The high voltage electric field breaks down the surface oxide insulating film instantly within 10ms, forming a stable conductive channel that reaches the conductor body directly. This fundamentally solves the industry problem that the low voltage of multimeters cannot penetrate the oxide film and the measured value deviates seriously from the true resistance of the conductor body.

[0039] Simultaneously, the oxide film breakdown and resistance measurement are completed synchronously through the same constant DC high voltage source, so that the breakdown process and the measurement process completely overlap in time and there is no equipment switching gap. This completely avoids the problem of secondary oxidation caused by the switching gap in the two-step method of high voltage breakdown first and then multimeter measurement in the existing improved scheme. For the first time, it realizes the direct and interference-free measurement of the actual body resistance of the conductor with oxide layer.

[0040] Based on this, the present invention maintains a constant output voltage throughout the entire detection cycle. In conjunction with a high-precision current measurement unit connected in series in the output circuit, the measurement deviation of the resistance value calculated based on Ohm's law can be controlled within 2.5%, thereby reducing the product misjudgment rate and solving the production pain point of high measurement error of existing multimeters and the misjudgment and scrapping of a large number of qualified products.

[0041] At the same time, the high and low voltage circuit switching steps and corresponding circuits are eliminated, the total testing time of a single channel is shortened, the testing efficiency is greatly improved compared with traditional multimeters and two-step methods, the circuit structure is greatly simplified, the equipment reliability is significantly improved, and it is fully adapted to the high-speed batch testing needs of industrial production lines. Attached Figure Description

[0042] Figure 1This is a schematic diagram of the structural process framework of the present invention.

[0043] In the diagram: 10, Microprocessor control module; 20, Display and operation module; 30, Data storage and communication module; 40, Automatic feeding mechanism; 50, Automatic sorting mechanism; 60, Real-time voltage calibration module; 70, Constant voltage DC power supply module; 80, Multiple safety protection module; 90, High-precision current measurement module. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Example:

[0046] like Figure 1 As shown, this embodiment proposes a resistance detection method for a surface oxide layer conductor. The method uses the same constant DC high-voltage source to simultaneously complete oxide film breakdown and resistance measurement, with the breakdown process and measurement process completely overlapping in time and without any equipment switching gap. Specifically, it includes the following steps:

[0047] S1: Connect the two conductive detection terminals of the conductor to be tested directly to the output circuit of the constant voltage DC power supply. The output circuit contains only a high-precision current measurement unit connected in series, without a high-voltage or low-voltage switching circuit.

[0048] S2: Apply a constant DC high voltage of 500V to 1500V to both ends of the conductor under test at one time. During the entire detection cycle, before the oxide insulating film breaks down, during the breakdown process, and after the current stabilizes, the output voltage of the constant DC high voltage remains constant.

[0049] S3: The oxide insulating film on the surface of the conductor under test is broken down within 10ms under the action of the constant DC high voltage electric field, forming a stable conductive channel;

[0050] S4: The high-precision current measurement unit starts to collect the loop current in real time at the same time as the oxide film breaks down, and reads the stable current value after the current stabilizes.

[0051] S5: The microprocessor directly calculates the actual resistance value of the conductor under test according to Ohm's law R=U / I, where U is the constant DC high voltage output value throughout the process;

[0052] S6: Compare the calculated actual resistance value with the preset standard range and automatically output the pass or fail judgment result.

[0053] In this embodiment, the inherent mode of low-voltage measurement with a multimeter is abandoned by the above method. A constant DC high voltage of 500V to 1500V is directly applied to the conductor under test. The high voltage electric field breaks down the surface oxide insulating film instantly within 10ms, forming a stable conductive channel that reaches the conductor body directly. This fundamentally solves the industry problem that the low voltage of the multimeter cannot penetrate the oxide film and the measured value deviates seriously from the true resistance of the conductor body.

[0054] Simultaneously, the oxide film breakdown and resistance measurement are completed synchronously through the same constant DC high voltage source, so that the breakdown process and the measurement process completely overlap in time and there is no equipment switching gap. This completely avoids the problem of secondary oxidation caused by the switching gap in the two-step method of high voltage breakdown first and then multimeter measurement in the existing improved scheme. For the first time, it realizes the direct and interference-free measurement of the actual body resistance of the conductor with oxide layer.

[0055] Based on this, the present invention maintains a constant output voltage throughout the entire detection cycle. In conjunction with a high-precision current measurement unit connected in series in the output circuit, the measurement deviation of the resistance value calculated based on Ohm's law can be controlled within 2.5%, thereby reducing the product misjudgment rate and solving the production pain point of high measurement error of existing multimeters and the misjudgment and scrapping of a large number of qualified products.

[0056] At the same time, the high and low voltage circuit switching steps and corresponding circuits are eliminated, the total testing time of a single channel is shortened, the testing efficiency is greatly improved compared with traditional multimeters and two-step methods, the circuit structure is greatly simplified, the equipment reliability is significantly improved, and it is fully adapted to the high-speed batch testing needs of industrial production lines.

[0057] Specifically, the preferred output voltage of the constant DC high voltage is 1000V, the output ripple coefficient is ≤0.5%, and the voltage calibration accuracy is stable within ±0.1%; the measurement range of the high-precision current measurement unit is 0.1mA~1A, the measurement accuracy is ±0.1%, and the response time is ≤1ms.

[0058] The breakdown time of the oxide insulating film is <10ms, the current stabilization time is ≤100ms, the total time for a single-channel complete test is ≤200ms, completely eliminating the influence of the secondary oxide film generated during equipment switching gaps on the measurement results, and the measurement deviation is ≤2.5%.

[0059] In this embodiment, by setting the preferred output voltage of the constant DC high voltage to 1000V, it can reliably break through the oxide insulating film of most commonly used industrial surface oxide layer conductors such as spark plugs, relay contacts, high voltage switch contacts, and cable joints, without causing any damage to the physical structure and electrical performance of the conductor under test. This overcomes the long-standing technical bias in the field that high voltage measurement inevitably damages the component under test.

[0060] Simultaneously, with an output ripple coefficient of ≤0.5% and a real-time voltage calibration accuracy of ±0.1%, the absolute stability and accuracy of the output voltage are ensured throughout the entire detection cycle before, during, and after oxide film breakdown, when the current is stable. This provides an unbiased voltage reference for resistance calculation based on Ohm's law, eliminating measurement errors introduced by voltage fluctuations at the source.

[0061] Based on this, by configuring a high-precision current measurement unit with a measurement range of 0.1mA to 1A, a measurement accuracy of ±0.1%, and a response time of ≤1ms, it not only fully covers the resistance detection range of commonly used conductors from a few ohms to several megaohms, but also can capture the current surge at the moment of oxide film breakdown and the stable current value after breakdown in real time and accurately, ensuring the timeliness and accuracy of current measurement; thus, the breakdown time of oxide insulating film is controlled within 10ms and the current stabilization time is controlled within 100ms, ultimately achieving a total detection time of ≤200ms for a single channel, which is more than 10 times more efficient than traditional detection methods, and fully meets the cycle time requirements of high-speed batch detection in industrial production lines.

[0062] Specifically, for dense conductors under test with an oxide film thickness greater than 5 μm, an adaptive step-by-step boost detection mode is adopted. Step S2 is as follows:

[0063] S21: The DC voltage applied across the conductor under test is gradually increased at a linear rate of 100V / s.

[0064] S22: Real-time monitoring of the circuit current change rate. When the current change rate exceeds the preset threshold, it is determined that the oxide insulation film has been broken down.

[0065] S23: Immediately lock the output voltage to 1000V and keep it constant, then proceed to step S3.

[0066] In this embodiment, the above-mentioned adaptive step-by-step voltage boost detection mode effectively solves the technical problem in the core technical solution that it is difficult to adapt to the detection of dense oxide film conductors with a thickness greater than 5μm, such as high-voltage switch contacts that have been stored for a long time and aging cable joints, by directly applying a constant high voltage of 1000V.

[0067] The voltage is slowly increased at a linear rate of 100V / s, avoiding the instantaneous energy impact caused by directly applying 1000V high voltage to the thick oxide film conductor, thus preventing the conductor under test from being burned or its electrical performance from being damaged. At the same time, it ensures the stability and controllability of the oxide film breakdown process. Furthermore, by monitoring the rate of change of the circuit current in real time rather than the absolute current value to determine the oxide film breakdown state, it can sensitively capture the current change signal at the moment of oxide film breakdown, effectively avoiding misjudgment or missed judgment caused by leakage current interference.

[0068] Specifically, a multi-channel parallel independent detection architecture is adopted, with N detection channels N≥2, which simultaneously detect N conductors to be tested. Each channel is equipped with an independent constant voltage DC power supply subunit and a high-precision current measurement subunit, and the detection process of each channel does not interfere with each other.

[0069] When there are 8 detection channels, the total detection time is ≤300ms when the 8 channels are detected in parallel, and a batch detection of no less than 12,000 conductors to be tested can be completed per hour.

[0070] In this embodiment, by configuring an independent constant voltage DC power supply subunit and a high-precision current measurement subunit for each detection channel, the high voltage output circuit of each channel is completely electrically isolated from the current acquisition circuit. This fundamentally solves the technical problems of crosstalk between channels and mutual influence of voltage fluctuations that are common in existing multi-channel detection devices. It ensures that the detection process of each channel is completely independent and does not interfere with each other. The measurement deviation of all channels can be stably controlled, ensuring the consistency and reliability of batch detection results.

[0071] Specifically, by utilizing the adjustable output characteristics of the same constant voltage DC power supply, insulation resistance detection and power frequency withstand voltage detection functions are integrated on the same device.

[0072] The insulation resistance detection step is as follows: apply a preset constant DC high voltage to the conductor to be tested, measure the leakage current of the circuit and calculate the insulation resistance value;

[0073] The withstand voltage test procedure is as follows: apply a preset constant high voltage to the conductor under test and maintain it for a specified time, and monitor whether the circuit current changes abruptly to determine whether the withstand voltage is qualified.

[0074] In this embodiment, by reusing the adjustable output characteristics of the core detection hardware, one-stop testing of the three core electrical properties of the surface oxide layer conductor—body resistance, insulation resistance, and power frequency withstand voltage—is achieved using the same device without adding an additional independent high-voltage generation module and measurement module.

[0075] This technology enables the completion of all three electrical performance tests on the conductor under test with a single wiring connection, completely avoiding the cumbersome operation of repeatedly disassembling and transferring the test piece between different devices in existing technologies. This shortens the full-item testing time for a single product and reduces manual operation steps, thereby lowering the labor intensity and skill requirements for operators.

[0076] Specifically, the conductor to be tested is an electrical component whose surface is prone to forming an oxide insulating film, including but not limited to spark plugs, relay contacts, high-voltage switch contacts, wiring terminals, and cable connectors.

[0077] A resistance detection device for a surface oxide layer conductor, employing a single constant voltage DC power supply module 70 to simultaneously achieve oxide film breakdown and resistance measurement, specifically including:

[0078] The constant voltage DC power supply module 70 is used to output a constant DC high voltage of 500V to 1500V throughout the entire detection cycle, and the output voltage remains unchanged throughout the entire detection cycle.

[0079] The high-precision current measurement module 90 is directly connected in series in the output circuit of the constant voltage DC power supply module 70, and is used to collect the circuit current in real time when the oxide film breaks down.

[0080] The real-time voltage calibration module 60 is electrically connected to the constant voltage DC power supply module 70 and is used to dynamically calibrate the output voltage to ensure that the voltage accuracy is stable within ±0.1%.

[0081] The microprocessor control module 10 is electrically connected to each of the above modules and is used to control the detection process, calculate the actual resistance value of the body according to Ohm's law, and output the judgment result.

[0082] The multiple safety protection module 80 is connected in parallel with the output circuit and integrates overcurrent protection, overvoltage protection, short circuit protection, and automatic discharge function after detection.

[0083] The display and operation module 20 is electrically connected to the microprocessor control module 10 and is used to display measurement data and judgment results, and provide a parameter setting interface.

[0084] In this embodiment, during measurement, after the power is turned on, the microprocessor control module 10 completes system initialization and self-test of each module. After the self-test is normal, it enters standby mode. The operator sets the output voltage, qualified resistance range and detection mode through the display and operation module 20, connects the conductor to be tested to the output circuit and starts the detection. The device first completes the circuit safety pre-check through the multiple safety protection module 80, and then the constant voltage DC power supply module 70 outputs a constant 500V~1500V DC high voltage throughout the process. The voltage real-time calibration module 60 dynamically calibrates the output voltage to ±0.1% accuracy. The oxide film on the surface of the conductor to be tested breaks down under the action of high voltage. The high-precision current measurement module 90 connected in series in the circuit synchronously collects the current signal in real time. After the current stabilizes, the microprocessor control module 10 reads the value, calculates the actual resistance value of the conductor according to Ohm's law and completes the qualified judgment. After the judgment is completed, the high voltage output is immediately cut off, triggering the automatic discharge function of the multiple safety protection module 80. After the discharge is completed, the display and operation module 20 displays the detection results. At the same time, the microprocessor control module 10 automatically stores all detection data. The above process can be repeated for continuous detection by replacing the conductor to be tested.

[0085] Through the above-mentioned modular integrated device architecture, with the core innovation of simultaneously realizing oxide film breakdown and resistance measurement with a single constant voltage DC power supply module 70, an integrated detection system without high and low voltage switching is constructed. This eliminates the need for two independent systems and corresponding high / low voltage switching circuits required by existing technologies, such as high voltage breakdown power supply and low voltage measurement power supply. The oxide film breakdown and resistance measurement share the same voltage reference and the same detection circuit. With constant high voltage output throughout the process and synchronous current acquisition, the breakdown time and measurement time are completely coincided. This completely eliminates the problem of secondary oxidation during equipment switching gaps from the structural source, and avoids system errors introduced by the inconsistency of the voltage references of the two power supplies.

[0086] The output circuit only connects the high-precision current measurement module 90 in series, reducing more than 90% of the vulnerable components such as switches and relays, significantly reducing the equipment failure rate and maintenance costs. In addition, all testing processes are uniformly scheduled by the microprocessor control module 10, eliminating individual differences caused by manual operation and ensuring the consistency and repeatability of test results for different batches and different operators.

[0087] The constant voltage DC power supply module 70 is dynamically closed-loop calibrated by the voltage real-time calibration module 60, stabilizing the output voltage accuracy within ±0.1%. Combined with the high-precision current measurement module 90 with a measurement accuracy of ±0.1% and a response time of ≤1ms, it provides an accurate voltage and current reference for resistance calculation based on Ohm's law, and finally achieves high-precision detection with a measurement deviation of ≤2.5%.

[0088] The multiple safety protection module 80 is connected in parallel with the output circuit, integrating real-time protection against overcurrent, overvoltage, and short circuit, as well as an automatic discharge function after detection. It can immediately cut off the high-voltage output when an abnormality is detected, and complete the discharge of the energy storage capacitor within 1 second after the detection is completed and output a safety warning. It eliminates the risk of high-voltage electric shock from the hardware level, and does not require manual intervention in the high-voltage circuit, which significantly improves the safety of operation.

[0089] Meanwhile, the microprocessor control module 10 enables full automation of the system's self-test, parameter configuration, safety pre-check, high-voltage output, data acquisition, calculation and judgment, automatic discharge, result display and data storage. Operators only need to complete the connection and start-up of the test piece, which greatly reduces skill requirements and labor intensity, and also provides a unified control foundation for subsequent expansion of multi-channel detection, automated loading and unloading and other functions.

[0090] Specifically, the preferred output voltage of the constant voltage DC power supply module 70 is 1000V, and the output ripple coefficient is ≤0.5%; the measurement range of the high-precision current measurement module 90 is 0.1mA~1A, the measurement accuracy is ±0.1%, and the response time is ≤1ms.

[0091] The automatic discharge function of the multiple safety protection module 80 is as follows: after the detection is completed, the parallel discharge circuit is immediately triggered to discharge the energy storage capacitor in the output circuit. The discharge time is ≤1s. After the discharge is completed, a safety prompt signal is automatically output.

[0092] In this embodiment, by precisely optimizing and coordinating the key parameters of the constant voltage DC power supply module 70, the high-precision current measurement module 90, and the multiple safety protection module 80, a solid hardware support is provided for the reliable, efficient, and safe operation of the core integrated detection technology. The preferred output voltage of the constant voltage DC power supply module 70 is set to 1000V, which can reliably break through the oxide insulating film of most commonly used industrial surface oxide layer conductors without causing any damage to the physical structure and electrical performance of the conductor under test. This overcomes the long-standing technical prejudice in the field that "high voltage measurement will inevitably damage the component under test." At the same time, with an output ripple coefficient of ≤0.5%, the stability of the output voltage is further guaranteed throughout the entire detection cycle, suppressing the interference of voltage fluctuations on the measurement results from the source.

[0093] Based on this, a high-precision current measurement module 90 with a measurement range of 0.1mA to 1A, a measurement accuracy of ±0.1%, and a response time of ≤1ms is configured. This module not only fully covers the resistance detection range of commonly used conductors from a few ohms to a few megaohms, meeting the detection needs of different products, but also can capture the current change signal at the moment of oxide film breakdown in real time and accurately, ensuring that the current acquisition is completely synchronized with the oxide film breakdown process, providing accurate and reliable current data for subsequent resistance calculation.

[0094] In addition, the automatic discharge function integrated in the multi-safety protection module 80 can immediately trigger the parallel discharge circuit after the test is completed, and complete the discharge of the energy storage capacitor in the output circuit within 1 second and automatically output a safety warning signal. This not only fundamentally eliminates the risk of electric shock caused by the residual high voltage of the energy storage capacitor and protects the personal safety of the operator, but also greatly shortens the waiting interval between two tests and further improves the continuous testing efficiency of the device.

[0095] Specifically, the detection device also includes a data storage and communication module 30, which is electrically connected to the microprocessor control module 10, for storing all detection data and supporting USB data export, RS485 industrial bus communication and 4G / 5G IoT remote communication.

[0096] The detection device also includes an automatic feeding mechanism 40 and an automatic sorting mechanism 50, both of which are electrically connected to the microprocessor control module 10, realizing fully unmanned operation of automatic feeding, automatic detection, automatic sorting and automatic data uploading of the conductive body to be tested.

[0097] In this embodiment, through seamless integration with the aforementioned automated equipment, unmanned operation of the entire process from raw material feeding and testing to finished product sorting is achieved, significantly reducing the company's labor costs; at the same time, all testing data can be uploaded to the company's MES system in real time through the data storage and communication module 30, realizing full lifecycle traceability of product quality and providing data support for production process optimization and quality control.

[0098] Of course, the automatic feeding mechanism 40 and the automatic sorting mechanism 50 can use multi-axis robotic arms to complete the gripping and sorting work.

[0099] Specifically, the detection device is a multi-channel batch detection device, which includes N independent detection channels N≥2. Each detection channel is equipped with an independent constant voltage DC power supply submodule, a high-precision current measurement submodule and a safety protection submodule. All detection channels are uniformly scheduled by the same microprocessor control module 10.

[0100] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for detecting the resistance of a conductive material with a surface oxide layer, characterized in that: The oxide film breakdown and resistance measurement are completed synchronously using the same constant DC high voltage source, and the breakdown process and the measurement process completely overlap in time with no equipment switching gap. The specific steps include: S1: Connect the two conductive detection terminals of the conductor to be tested directly to the output circuit of the constant voltage DC power supply. The output circuit contains only a high-precision current measurement unit connected in series, without a high-voltage or low-voltage switching circuit. S2: Apply a constant DC high voltage of 500V to 1500V to both ends of the conductor under test at one time. During the entire detection cycle, before the oxide insulating film breaks down, during the breakdown process, and after the current stabilizes, the output voltage of the constant DC high voltage remains constant. S3: The oxide insulating film on the surface of the conductor under test is broken down within 10ms under the action of the constant DC high voltage electric field, forming a stable conductive channel; S4: The high-precision current measurement unit starts to collect the loop current in real time at the same time as the oxide film breaks down, and reads the stable current value after the current stabilizes. S5: The microprocessor directly calculates the actual resistance value of the conductor under test according to Ohm's law R=U / I, where U is the constant DC high voltage output value throughout the process; S6: Compare the calculated actual resistance value with the preset standard range and automatically output the pass or fail judgment result.

2. The resistance detection method for a surface oxide layer conductive body according to claim 1, characterized in that: The preferred output voltage of the constant DC high voltage is 1000V, the output ripple coefficient is ≤0.5%, and the voltage calibration accuracy is stable within ±0.1%; the measurement range of the high-precision current measurement unit is 0.1mA~1A, the measurement accuracy is ±0.1%, and the response time is ≤1ms. The breakdown time of the oxide insulating film is <10ms, the current stabilization time is ≤100ms, the total time for a single-channel complete test is ≤200ms, completely eliminating the influence of the secondary oxide film generated during equipment switching gaps on the measurement results, and the measurement deviation is ≤2.5%.

3. The resistance detection method for a surface oxide layer conductive body according to claim 1, characterized in that: For dense conductors under test with an oxide film thickness greater than 5 μm, an adaptive step-by-step boost detection mode is adopted. Step S2 is as follows: S21: The DC voltage applied across the conductor under test is gradually increased at a linear rate of 100V / s. S22: Real-time monitoring of the circuit current change rate. When the current change rate exceeds the preset threshold, it is determined that the oxide insulation film has been broken down. S23: Immediately lock the output voltage to 1000V and keep it constant, then proceed to step S3.

4. The resistance detection method for a surface oxide layer conductive body according to claim 1, characterized in that: A multi-channel parallel independent detection architecture is adopted, with N detection channels N≥2, which simultaneously detects N conductors to be tested. Each channel is equipped with an independent constant voltage DC power supply subunit and a high-precision current measurement subunit, and the detection process of each channel does not interfere with each other. When there are 8 detection channels, the total detection time is ≤300ms when the 8 channels are detected in parallel, and a batch detection of no less than 12,000 conductors to be tested can be completed per hour.

5. The resistance detection method for a surface oxide layer conductive body according to claim 1, characterized in that: By utilizing the adjustable output characteristics of the same constant voltage DC power supply, insulation resistance detection and power frequency withstand voltage detection functions can be integrated on the same device. The insulation resistance detection step is as follows: apply a preset constant DC high voltage to the conductor to be tested, measure the leakage current of the circuit and calculate the insulation resistance value; The withstand voltage test procedure is as follows: apply a preset constant high voltage to the conductor under test and maintain it for a specified time, and monitor whether the circuit current changes abruptly to determine whether the withstand voltage is qualified.

6. The resistance detection method for a surface oxide layer conductive body according to claim 1, characterized in that: The conductor to be tested is an electrical component whose surface easily forms an oxide insulating film, including but not limited to spark plugs, relay contacts, high-voltage switch contacts, wiring terminals, and cable connectors.

7. A resistance detection device for a surface oxide conductive body implementing the method of any one of claims 1-6, characterized in that: A single constant voltage DC power supply module (70) is used to simultaneously achieve oxide film breakdown and resistance measurement, specifically including: The constant voltage DC power supply module (70) is used to output a constant DC high voltage of 500V to 1500V throughout the entire detection cycle, and the output voltage remains unchanged throughout the entire detection cycle. A high-precision current measurement module (90) is directly connected in series in the output circuit of the constant voltage DC power supply module (70) to collect the circuit current in real time while the oxide film breaks down; The voltage real-time calibration module (60) is electrically connected to the constant voltage DC power supply module (70) and is used to dynamically calibrate the output voltage to ensure that the voltage accuracy is stable within ±0.1%. The microprocessor control module (10) is electrically connected to each of the above modules and is used to control the detection process, calculate the actual resistance value of the body according to Ohm's law and output the judgment result. A multi-safety protection module (80) is connected in parallel with the output circuit, integrating overcurrent protection, overvoltage protection, short circuit protection, and automatic discharge function after detection; The display and operation module (20) is electrically connected to the microprocessor control module (10) and is used to display measurement data and judgment results, and to provide a parameter setting interface.

8. The resistance detection device for a surface oxide conductive layer according to claim 7, characterized in that: The preferred output voltage of the constant voltage DC power supply module (70) is 1000V, and the output ripple coefficient is ≤0.5%; the measurement range of the high-precision current measurement module (90) is 0.1mA~1A, the measurement accuracy is ±0.1%, and the response time is ≤1ms. The automatic discharge function of the multiple safety protection module (80) is as follows: after the detection is completed, the parallel discharge circuit is immediately triggered to discharge the energy storage capacitor in the output circuit. The discharge time is ≤1s. After the discharge is completed, a safety prompt signal is automatically output.

9. The resistance detection device for a surface oxide layer conductive body according to claim 7, characterized in that: The detection device also includes a data storage and communication module (30), which is electrically connected to the microprocessor control module (10) for storing all detection data and supporting USB data export, RS485 industrial bus communication and 4G / 5G IoT remote communication; The detection device also includes an automatic feeding mechanism (40) and an automatic sorting mechanism (50), both of which are electrically connected to the microprocessor control module (10) to realize the fully unmanned operation of automatic feeding, automatic detection, automatic sorting and automatic data uploading of the conductive body to be tested.

10. The resistance detection device for a surface oxide layer conductive body according to claim 7, characterized in that: The detection device is a multi-channel batch detection device, which includes N independent detection channels N≥2. Each detection channel is equipped with an independent constant voltage DC power supply submodule, a high-precision current measurement submodule and a safety protection submodule. All detection channels are uniformly scheduled by the same microprocessor control module (10).

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