Carbon potential detection device for carburizing multi-purpose furnace

Abstract

The invention belongs to the technical field of carbon potential dynamic detection, and particularly relates to a carbon potential detection device for a carburizing multi-purpose furnace. During working, clean air is injected into an air storage tank, a first electromagnetic valve corresponding to one air storage bin is opened, a second air pump and a second electromagnetic valve are closed, inflation is carried out, a first electromagnetic valve corresponding to the other air storage bin is closed, and the first air pump and the second electromagnetic valve are closed; a second air pump and a second electromagnetic valve are opened, and clean gas is introduced into the oxygen probe for deflation; after the time is set, the working modes of the two gas storage bins are changed. By arranging the air storage box with the partition plate, the inner cavity is equally divided into the two air storage bins, and the first electromagnetic valve, the second electromagnetic valve and the second air pump are matched, so that stable control over the flow of air introduced into the air inlet end of the oxygen probe is achieved. The two air storage bins can work alternately, so that the continuity of air supply is ensured, the carbon potential measurement error caused by air flow fluctuation is avoided, and the accuracy and reliability of carbon potential detection are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of carbon potential dynamic detection, and particularly relates to a carbon potential detection device for a carburizing multi-purpose furnace. BACKGROUND

[0002] As one of the core processes of chemical heat treatment, carburizing is widely applied to the surface strengthening of low-carbon steel parts. The process places the workpiece in a carburizing medium, heats it to austenitizing temperature and keeps it, so that active carbon atoms are penetrated into the surface layer of the workpiece, thereby obtaining a composite structure of high-carbon surface and low-carbon core. In order to accurately control the quality of the carburized layer, it is necessary to monitor the carbon potential in real time during the process. The carbon potential reflects the strength of the furnace gas carburizing capacity, and is usually measured indirectly by an oxygen probe: by detecting the oxygen partial pressure in the carbon-containing atmosphere, the corresponding carbon potential value is converted according to the atmosphere equilibrium reaction principle.

[0003] In the prior art, when the carbon potential is detected by the oxygen probe, air is directly or filtered and then directly introduced into the air inlet end of the oxygen probe. However, this method of directly introducing air may have unstable air flow, thereby causing errors in the measurement results.

[0004] Therefore, a carbon potential detection device for a carburizing multi-purpose furnace is provided. SUMMARY

[0005] The purpose of the present application is to provide a carbon potential detection device for a carburizing multi-purpose furnace to solve the above problems.

[0006] To achieve the above purpose, the present application provides the following scheme:

[0007] A carbon potential detection device for a carburizing multi-purpose furnace, comprising: a mounting plate fixedly installed on the outer side wall of a furnace body, an outer box body being fixedly connected to the side of the mounting plate away from the furnace body, a gas storage tank being arranged in the outer box body, the gas outlet end of the gas storage tank being in communication with the air inlet end of an oxygen probe through a second gas conveying pipe, the detection end of the oxygen probe extending into the furnace body, the gas inlet end of the gas storage tank being in communication with a first gas pump through a first gas conveying pipe, the first gas pump being arranged in the outer box body.

[0008] The inner cavity of the gas storage tank is equally divided into two gas storage compartments by a partition plate, the two gas storage compartments being in communication with the second gas conveying pipe and the first gas conveying pipe respectively, a first electromagnetic valve being arranged between the gas storage compartment and the first gas conveying pipe, a second electromagnetic valve being arranged between the gas storage compartment and the second gas conveying pipe, and a second gas pump being arranged in the gas storage compartment, the gas outlet end of the second gas pump being in communication with the second electromagnetic valve.

[0009] Preferably, a motor is fixedly connected to the mounting plate, an output shaft of the motor is coaxially fixedly connected with a transmission shaft, the transmission shaft is rotatably connected with the mounting plate through a sealing slip ring, the transmission shaft penetrates into the furnace body and is coaxially fixedly connected with a first bevel gear, the first bevel gear is engaged with a second bevel gear, the second bevel gear is coaxially fixedly connected with a rotating shaft at one end, the rotating shaft is rotatably connected with the mounting plate through a support, a fan blade is fixedly connected with the other end of the rotating shaft, and the fan blade is correspondingly arranged with a detection end of the oxygen probe.

[0010] Preferably, a calibration tube is fixedly connected to the mounting plate, the calibration tube is arranged in an L shape and downwardly arranged at one end in the furnace body, a gravity sensor is detachably connected with one end of the calibration tube penetrating out of the furnace body, the gravity sensor is sealingly arranged between the calibration tube, a pull rope is connected with a measurement end of the gravity sensor, the pull rope is arranged in the calibration tube, a test piece is fixedly connected with the other end of the pull rope penetrating out of the calibration tube, and the maximum width of the test piece is smaller than the inner diameter of the calibration tube.

[0011] Preferably, the gas outlet end of the second gas pipe is communicated with the gas inlet end of a three-way valve, the gas outlet end of the three-way valve is respectively communicated with the gas inlet end of the oxygen probe and a purge pipe, the purge pipe penetrates into the furnace body and is communicated with a purge ring, the purge ring is sleeved on the outside of the oxygen probe and is correspondingly arranged with the detection end of the oxygen probe.

[0012] Preferably, the gas inlet end of the first gas pump is communicated with a filter, and the filter is arranged in the outer box body.

[0013] Preferably, the filter comprises a shell, one end of the shell is communicated with a gas inlet pipe penetrating out of the outer box body, and the other end of the shell is communicated with the gas inlet end of the first gas pump through a gas outlet pipe.

[0014] The shell is sequentially provided with a filter layer, a first adsorption layer and a second adsorption layer in the direction of gas flow.

[0015] Preferably, a gas pressure sensor is arranged in the gas storage bin.

[0016] Preferably, a multi-gas measurement sensor is arranged in the outer box body, and a measurement end of the multi-gas measurement sensor penetrates into the furnace body.

[0017] Preferably, a temperature sensor is arranged in the outer box body, a measurement end of the temperature sensor penetrates into the furnace body, and the measurement end of the temperature sensor is close to the detection end of the oxygen probe.

[0018] Preferably, a pulley is arranged in the calibration tube, an axis of the pulley is horizontally arranged, and the pull rope is in rolling contact with the pulley.

[0019] Compared with the prior art, the present application has the following advantages and technical effects:

[0020] In operation, clean air is injected into the gas storage tank by the first air pump, when injecting, the first electromagnetic valve corresponding to one of the gas storage compartments is opened, the second air pump and the second electromagnetic valve are closed, and the air is filled, the first electromagnetic valve corresponding to the other gas storage compartment is closed, and the second air pump and the second electromagnetic valve are opened, and the clean gas is introduced into the oxygen probe, and the air is discharged; after setting the time, the two gas storage compartments change the working mode, and the second air pump is further arranged to ensure the stability of the gas flow, so that the stable control of the air flow introduced into the air inlet end of the oxygen probe is realized.

[0021] The present application divides the inner cavity into two gas storage compartments by arranging the gas storage tank with a partition plate, and cooperates with the first electromagnetic valve, the second electromagnetic valve and the second air pump, so that the stable control of the air flow introduced into the air inlet end of the oxygen probe is realized. The two gas storage compartments can work alternately to ensure the continuity of gas supply, and the carbon potential measurement error caused by air flow fluctuation is avoided, so that the accuracy and reliability of carbon potential detection are improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings:

[0023] Fig. 1 It is a schematic diagram of the overall structure of the present application;

[0024] Fig. 2 It is a schematic diagram of the internal structure of the filter in the present application;

[0025] Among them, 1, mounting plate; 2, motor; 3, transmission shaft; 4, first bevel gear; 5, second bevel gear; 6, fan blade; 7, rotating shaft; 8, bracket; 9, multi-gas measurement sensor; 10, temperature sensor; 11, purge pipe; 12, oxygen probe; 13, calibration pipe; 14, pull rope; 15, test piece; 16, pulley; 17, gravity sensor; 18, outer box; 19, filter; 20, first air pump; 21, first gas pipe; 22, first electromagnetic valve; 23, gas storage tank; 24, air pressure sensor; 25, second air pump; 26, partition plate; 27, second electromagnetic valve; 28, three-way valve; 29, purge ring; 1901, shell; 1902, air inlet pipe; 1903, air outlet pipe; 1904, filter layer; 1905, first adsorption layer; 1906, second adsorption layer. DETAILED DESCRIPTION

[0026] Clearly, the embodiments described are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0027] In order to make the above objectives, characteristics and advantages of the present application more apparent, further specific embodiments of the present application will be described in detail below with reference to the drawings and specific embodiments.

[0028] With reference to Figs. 1-2 The present application discloses a carbon potential detection device for a carburizing multi-purpose furnace, comprising: a mounting plate 1 fixedly installed on the outer side wall of a furnace body, an outer box body 18 fixedly connected to the side of the mounting plate 1 away from the furnace body, a gas storage tank 23 arranged in the outer box body 18, a gas outlet end of the gas storage tank 23 in communication with a gas inlet end of an oxygen probe 12 through a second gas conveying pipe, a detection end of the oxygen probe 12 extending into the furnace body, a gas inlet end of the gas storage tank 23 in communication with a first gas pump 20 through a first gas conveying pipe 21, and the first gas pump 20 arranged in the outer box body 18.

[0029] The inner cavity of the gas storage tank 23 is equally divided into two gas storage compartments by a partition plate 26, the two gas storage compartments are in communication with the second gas conveying pipe and the first gas conveying pipe 21 respectively, a first electromagnetic valve 22 is arranged between each gas storage compartment and the first gas conveying pipe 21, a second electromagnetic valve 27 is arranged between each gas storage compartment and the second gas conveying pipe, and a second gas pump 25 is arranged in each gas storage compartment, with the gas outlet end of the second gas pump 25 in communication with the second electromagnetic valve 27.

[0030] The first gas pump 20 pumps external air into the gas storage tank 23 through the first gas conveying pipe 21. The inner cavity of the gas storage tank 23 is equally divided into two gas storage compartments by the partition plate 26, and the gas charging and gas supplying states of the two gas storage compartments can be switched by controlling the opening and closing of the first electromagnetic valve 22 and the second electromagnetic valve 27. When a certain gas storage compartment needs to supply gas to the oxygen probe 12, the second gas pump 25 in the gas storage compartment is started to convey the air with stable gas pressure stored in the gas storage compartment to the gas inlet end of the oxygen probe 12 through the second gas conveying pipe.

[0031] The gas is pre-stored in the gas storage tank 23 and is stably output by the second gas pump 25, which effectively eliminates the flow fluctuation possibly caused by the direct gas supply of the first gas pump 20, and provides the oxygen probe 12 with reference air with constant flow, thereby significantly improving the accuracy of carbon potential measurement. The double-gas-storage-compartment design realizes continuous and uninterrupted gas supply.

[0032] The scheme is further optimized. A motor 2 is fixedly connected to the mounting plate 1. A transmission shaft 3 is coaxially fixed to the output shaft of the motor 2. The transmission shaft 3 is rotatably connected to the mounting plate 1 through a sealing slip ring. The transmission shaft 3 passes into the furnace body and is coaxially fixed to a first bevel gear 4. The first bevel gear 4 meshes with a second bevel gear 5. The second bevel gear 5 is coaxially fixed to one end of a rotating shaft 7. The rotating shaft 7 is rotatably connected to the mounting plate 1 through a bracket 8. A fan blade 6 is fixedly installed at the other end of the rotating shaft 7. The fan blade 6 is set to correspond to the detection end of the oxygen probe 12.

[0033] Motor 2 drives transmission shaft 3 to rotate, and transmission shaft 3 is rotatably connected to mounting plate 1 through a sealing slip ring. The first bevel gear 4 at the end of transmission shaft 3 drives the second bevel gear 5 and rotating shaft 7 to rotate, which ultimately causes the fan blade 6 fixed to the other end of rotating shaft 7 to rotate, so as to balance the atmosphere in the furnace. At the same time, the rotation of fan blade 6 agitates the furnace gas around the detection end of oxygen probe 12, breaks the local atmosphere stagnation layer, and enables oxygen probe 12 to sense the carbon potential of the overall atmosphere in the furnace more quickly and accurately, thereby improving the detection response speed and the ability to sense the true state of the furnace gas.

[0034] In a further optimized design, a calibration tube 13 is fixedly attached to the mounting plate 1. The calibration tube 13 is L-shaped with one end facing downwards inside the furnace. A gravity sensor 17 is detachably connected to one end of the calibration tube 13 that extends out of the furnace. The gravity sensor 17 and the calibration tube 13 are sealed together. A pull rope 14 is connected to the measuring end of the gravity sensor 17. The pull rope 14 is inserted inside the calibration tube 13. The other end of the pull rope 14 extends out of the calibration tube 13 and is fixedly attached to a test piece 15. The maximum width of the test piece 15 is smaller than the inner diameter of the calibration tube 13.

[0035] The specimen 15 is suspended by a rope 14, the other end of which is connected to the measuring end of a gravity sensor 17 extending out of the furnace body. During the carburizing process, the surface carbonization of the specimen 15 leads to an increase in weight, and this change is monitored in real time by the gravity sensor 17.

[0036] By measuring the real-time weight gain of specimen 15 during the carburizing process, the actual carbon content on its surface can be calculated, thus providing a direct and reliable calibration benchmark for the carbon potential value indirectly measured by oxygen probe 12, verifying and ensuring the accuracy of the carbon potential control system.

[0037] In a further optimized design, the outlet of the second gas supply pipe is connected to the inlet of a three-way valve 28. The outlet of the three-way valve 28 is connected to the inlet of the oxygen probe 12 and the purge pipe 11, respectively. The purge pipe 11 extends into the furnace body and is connected to a purge ring 29. The purge ring 29 is loosely fitted on the outside of the oxygen probe 12 and is set to correspond to the detection end of the oxygen probe 12.

[0038] The inlet of the three-way valve 28 is connected to the second gas supply pipe, and its two outlets are connected to the inlet of the oxygen probe 12 and the purge pipe 11, respectively. By switching the three-way valve 28, a stable airflow can enter the purge pipe 11 and be ejected from the purge ring 29 at the end. The purge ring 29 is loosely fitted on the outside of the oxygen probe 12 and aligned with its detection end.

[0039] The device utilizes its own stable airflow to periodically purge and clean the detection end of the oxygen probe 12, effectively removing any deposits such as carbon black that may adhere to its surface, preventing probe contamination and failure, ensuring measurement stability, and extending its service life.

[0040] In a further optimized design, the air inlet of the first air pump 20 is connected to a filter 19, which is located inside the outer casing 18.

[0041] When the first air pump 20 draws in air, it first purifies the air by passing it through the filter 19. The outlet of the filter 19 is connected to the air inlet of the first air pump 20 through a pipe.

[0042] The reference air supplied to the oxygen probe 12 is purified at the source, removing impurities and preventing these substances from contaminating or damaging the oxygen probe 12, thus ensuring the normal working conditions and measurement reliability of the oxygen probe 12.

[0043] In a further optimized design, the filter 19 includes a housing 1901, one end of which is connected to an air inlet pipe 1902, which extends out of the outer casing 18, and the other end of the housing 1901 is connected to the air inlet of the first air pump 20 via an air outlet pipe 1903.

[0044] The outer casing 1901 is provided with a filter layer 1904, a first adsorption layer 1905 and a second adsorption layer 1906 arranged sequentially along the gas flow direction.

[0045] Outside air enters the housing 1901 of the filter 19 through the air inlet pipe 1902, and is purified by passing through the internal filter layer 1904, the first adsorption layer 1905 and the second adsorption layer 1906 in sequence. The purified air flows to the first air pump 20 through the air outlet pipe 1903.

[0046] Through multi-stage filtration and adsorption, the reference air is deeply purified, ensuring that the air entering the oxygen probe 12 is clean and dry, and avoiding the influence of gaseous impurities on the measurement accuracy of the oxygen probe 12.

[0047] The first adsorption layer 1905 is made of activated carbon, and the second adsorption layer 1906 is made of a solid desiccant.

[0048] The design was further optimized by installing a pressure sensor 24 inside the gas storage chamber.

[0049] A pressure sensor 24 is installed inside the gas storage chamber to monitor the gas pressure inside the chamber in real time. It provides real-time data feedback for the gas pressure management of the gas storage chamber and can be linked with the first air pump 20, the second air pump 25 and the solenoid valve to realize automatic adjustment and replenishment of the gas storage chamber pressure, ensuring that the airflow pressure supplied to the oxygen probe 12 remains stable.

[0050] The design was further optimized by installing a multi-gas measurement sensor 9 inside the outer casing 18, with the measuring end of the multi-gas measurement sensor 9 extending into the furnace body.

[0051] The multi-gas measurement sensor 9 is installed inside the outer casing 18, with its measuring end extending into the furnace to perform real-time analysis of various gas components in the furnace atmosphere. This provides more comprehensive furnace gas information, which can be complemented and verified with the carbon potential value, providing more dimensions of evidence for process control and enhancing the monitoring capability of complex carburizing atmospheres.

[0052] To further optimize the design, a temperature sensor 10 is installed inside the outer casing 18. The measuring end of the temperature sensor 10 extends into the furnace body and is close to the detection end of the oxygen probe 12. The temperature sensor 10, installed inside the outer casing 18 with its measuring end extending into the furnace and close to the detection end of the oxygen probe 12, is used to monitor the local temperature at the location of the oxygen probe 12 in real time. Since the output signal of the oxygen probe 12 is highly sensitive to temperature, accurately measuring the temperature at its location allows for temperature compensation calculations of the carbon potential measurement, further eliminating measurement errors introduced by temperature fluctuations.

[0053] The design is further optimized by installing a pulley 16 inside the calibration tube 13. The axis of the pulley 16 is horizontally positioned, and the pull rope 14 rolls in contact with the pulley 16. The pulley 16, installed inside the calibration tube 13 with its axis horizontally positioned, passes over the pulley 16 to form a rolling contact. This transforms the sliding friction between the pull rope 14 and the calibration tube 13 into rolling friction, greatly reducing the frictional force when the pull rope 14 moves. This ensures the gravity sensor 17's sensitive measurement of changes in the weight of the sample 15 and improves the accuracy of the calibration data.

[0054] The overall work process is as follows:

[0055] First, driven by the first air pump 20, external air is purified by the filter 19 and then delivered to the air storage tank 23 through the first air supply pipe 21. The internal partition 26 of the air storage tank 23 divides its cavity into two independent air storage chambers. By controlling the opening and closing of the first solenoid valve 22 and the second solenoid valve 27 corresponding to each air storage chamber, the two air storage chambers can alternately perform inflation and deflation operations. When one air storage chamber is in deflation mode, its internal second air pump 25 starts, smoothly outputting the pre-stored, pressure-stable air from the chamber through the second air supply pipe. The pressure sensor 24 monitors the pressure status inside the air storage chamber in real time, providing feedback for the stable operation of the system.

[0056] A stable airflow reaches the three-way valve 28 through the second gas supply pipe. In normal measurement mode, the three-way valve 28 directs the airflow to the inlet of the oxygen probe 12, providing it with constant reference air. The detection end of the oxygen probe 12 extends into the furnace, indirectly determining the carbon potential by detecting the oxygen partial pressure of the atmosphere inside the furnace.

[0057] To optimize the detection environment, motor 2 drives the fan blades 6 at the end of shaft 7 to rotate via transmission shaft 3, first bevel gear 4, and second bevel gear 5, agitating the furnace gas around the detection end of oxygen probe 12 to make it more representative. Simultaneously, temperature sensor 10 monitors the temperature near oxygen probe 12 for temperature compensation of carbon potential; multi-gas measurement sensor 9 provides auxiliary analysis of various gas components within the furnace.

[0058] During initial operation, the accuracy of the carbon potential measurement needs to be verified, and the device is equipped with a calibration function. The specimen 15 is suspended in the carburizing atmosphere inside the furnace by a rope 14, the other end of which is connected to a gravity sensor 17 outside the furnace via a pulley 16 inside the calibration tube 13. By monitoring the increase in weight of the specimen 15 during the carburizing process in real time, the actual carbon content on its surface can be calculated, thus directly calibrating the measurement results of the oxygen probe 12. Calibration is performed periodically, rather than requiring full-process calibration.

[0059] When it is necessary to clean the detection end of the oxygen probe 12, the three-way valve 28 can be switched to direct the stable airflow to the purge pipe 11. The airflow is sprayed out from the purge ring 29 at the end to purge the detection end of the oxygen probe 12 and remove surface deposits.

[0060] Oxygen probe 12, motor 2, multi-gas measurement sensor 9, temperature sensor 10, gravity sensor 17, first air pump 20, first solenoid valve 22, air pressure sensor 24, second air pump 25, second solenoid valve 27, and three-way valve 28 are all electrically connected to the controller, which is an industrial control computer.

[0061] The controller receives pressure data from the pressure sensors 24 in each gas storage chamber in real time and controls the two gas storage chambers to work alternately according to preset logic. For example, when the pressure in gas storage chamber 1 is lower than the set lower limit, the controller performs the following operations: closes the second solenoid valve 27 of that chamber to stop its gas supply. Opens the second solenoid valve 27 of gas storage chamber 2 and starts its internal second air pump 25, allowing gas to be supplied to the oxygen probe 12 from chamber 2. At the same time, opens the first solenoid valve 22 of chamber 1 and starts the first air pump 20 to fill chamber 1 until its pressure sensor 24 shows that the pressure has reached the set upper limit, then closes the first solenoid valve 22 to stop filling. Through this control, it is ensured that one gas storage chamber is always supplying reference air to the oxygen probe 12 at a stable pressure, achieving continuous gas supply and flow stability.

[0062] After receiving the command to start the system measurement, the controller automatically starts motor 2, driving fan blade 6 to rotate continuously, stirring the furnace gas around the detection end of oxygen probe 12 to ensure the representativeness of the measured atmosphere. The controller reads the actual temperature near oxygen probe 12 detected by temperature sensor 10 in real time, and uses this data to perform temperature compensation calculation on the original potential signal output by oxygen probe 12 to obtain a more accurate carbon potential value.

[0063] The controller synchronously acquires the potential signal from the oxygen probe 12, the gas composition data from the multi-gas measurement sensor 9, and the compensated temperature data. By combining these parameters, the carbon potential value is calculated using a more complex mathematical model (such as a carbon potential calculation model that considers changes in CO content), or the single measurement result of the oxygen probe 12 is cross-validated to improve the accuracy and reliability of carbon potential control.

[0064] The controller can automatically initiate the calibration process at preset time intervals or when abnormal fluctuations in carbon potential are detected. During calibration, the controller continuously records the weight data of the specimen 15 transmitted back by the gravity sensor 17. By calculating the weight increment over a period of time and based on the surface area of ​​the specimen, the actual carbon increment can be accurately calculated. The controller compares this calculation result with the average carbon potential measured by the oxygen probe 12 during the same time period. If a significant deviation exists, the controller can automatically generate a calibration coefficient to correct subsequent measurements by the oxygen probe 12, or issue an alarm to prompt maintenance.

[0065] The process of automatic calibration control can be divided into four stages: preparation, measurement, comparison and decision-making, and execution.

[0066] Phase 1: Preparation and Triggering

[0067] Triggering conditions: 1. Time trigger: The controller has a real-time clock inside, which will automatically trigger when the preset calibration interval is reached (e.g., every 24 hours or after every 10 batches produced).

[0068] 2. Event Trigger: The controller continuously monitors the output signal of oxygen probe 12. If the signal fluctuation exceeds the normal range or the carbon potential value fails to reach the target for an extended period under the set parameters, the controller determines it as "abnormal fluctuation" and automatically triggers calibration to diagnose the problem.

[0069] Calibration initialization: The controller records the calibration start time t0. The initial weight W0 of the specimen 15 is read and recorded by gravity sensor 17. To ensure accuracy, multiple samples may be taken within a short period of time and the average value may be calculated.

[0070] Phase Two: Process Execution and Data Collection

[0071] Synchronous monitoring: Direct measurement channel: Throughout the calibration cycle (e.g., for 30 minutes), the controller records the specimen weight data transmitted back by gravity sensor 17 at a certain frequency (e.g., once per second).

[0072] Indirect measurement channel: At the same time, the controller records the carbon potential value CP_oxygen(t) measured and calculated by oxygen probe 12 at the same time frequency.

[0073] Data preprocessing: After the calibration cycle is completed, the controller records the end time t1 and the final weight W1 of the specimen.

[0074] Calculate the actual carbon increment:

[0075] The weight increment ΔW = W1 - W0, and the surface area S of specimen 15 is known (this parameter is a fixed value and has been pre-input into the controller).

[0076] Calculate the actual carbon increment per unit area: ΔC_actual = ΔW / S (unit: mg / cm² or g / cm²). This value ΔC_actual represents the actual amount of carbon absorbed by the specimen surface during the calibration period.

[0077] Phase Three: Data Comparison and Decision-Making Logic

[0078] This is the most crucial step: the controller correlates the two measurement results.

[0079] Theoretical conversion: The controller needs to convert the oxygen probe readings into the "theoretically required increase in carbon content" in order to compare them with the direct measurement results. It calculates the average carbon potential CP_avg measured by oxygen probe 12 during the time interval t0 to t1.

[0080] According to the theory of steel carburization, at a specific temperature, the carbon potential corresponds to the equilibrium carbon content on the surface of the steel part. Within a certain time interval Δt = t1 - t0, the increase in surface carbon concentration can be approximately estimated using a diffusion model (such as Fick's law). The controller has a simplified mathematical model that uses CP_avg and time Δt to calculate the theoretical carbon increment per unit area ΔC_theoretical under this carbon potential environment.

[0081] Deviation calculation: The controller calculates the deviation between the actual value and the theoretical value.

[0082] Deviation rate δ=(ΔC_actual-ΔC_theoretical) / ΔC_theoretical*100%

[0083] Alternatively, calculate the absolute error.

[0084] Decision logic: The controller compares the deviation rate δ with a preset allowable deviation threshold (e.g., ±3%).

[0085] Scenario 1: The deviation is within the allowable range (|δ|≤ threshold)

[0086] Judgment: The oxygen probe is working properly and the measurement is accurate.

[0087] Action: No corrections required. Calibration records are archived. The system continues to operate normally.

[0088] Scenario 2: Deviation exceeds the allowable range (|δ|>threshold)

[0089] Assessment: The oxygen probe is at risk of measurement drift or failure.

[0090] Action: Enter the "correction" process.

[0091] Phase Four: Implementation Correction

[0092] Generating calibration coefficients: The simplest correction method is to use linear correction. The controller will automatically generate a calibration coefficient K.

[0093] K=ΔC_actual / ΔC_theoretical.

[0094] Subsequently, when the controller reads the raw signal from oxygen probe 12 and calculates the carbon potential, it multiplies the result by this coefficient K:

[0095] The corrected carbon potential CP_corrected = K * CP_oxygen.

[0096] Alarms and prompts: Simultaneously, if the deviation rate δ is very large (e.g., exceeding 10%), it may mean that the oxygen probe has seriously failed or is damaged, and linear correction is unreliable. The controller will trigger a higher-level alarm and display messages such as "Oxygen probe requires maintenance" or "Calibration failed, please check the oxygen probe" on the human-machine interface (e.g., touchscreen), prompting the operator to intervene manually, replace, or repair the probe.

[0097] The controller can automatically perform a cleaning operation according to a preset program (such as every few hours) or based on the degree of signal attenuation of the oxygen probe 12 (determined by the possibility of carbon buildup). The controller sends a command to switch the three-way valve 28, changing the stable airflow originally directed to the inlet of the oxygen probe 12 to the purge pipe 11 and purge ring 29. The high-speed airflow purges and cleans the detection end of the oxygen probe 12. After a period of time, the controller then controls the three-way valve 28 to return to the normal measurement state.

[0098] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0099] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A carbon potential detection device for a multi-purpose carburizing furnace, characterized in that, include: Mounting plate (1), the mounting plate (1) is fixedly installed on the outer wall of the furnace body, the mounting plate (1) is fixedly connected to an outer box (18) on the side away from the furnace body, the outer box (18) is provided with a gas storage box (23), the gas outlet of the gas storage box (23) is connected to the gas inlet of the oxygen probe (12) through the second gas supply pipe, the detection end of the oxygen probe (12) extends into the furnace body, the gas inlet of the gas storage box (23) is connected to the first gas pump (20) through the first gas supply pipe (21), the first gas pump (20) is set in the outer box (18); The inner cavity of the gas storage box (23) is divided into two gas storage chambers by a partition (26). The two gas storage chambers are respectively connected to the second gas supply pipe and the first gas supply pipe (21). A first solenoid valve (22) is provided between the gas storage chamber and the first gas supply pipe (21). A second solenoid valve (27) is provided between the gas storage chamber and the second gas supply pipe. A second air pump (25) is provided in the gas storage chamber. The air outlet of the second air pump (25) is connected to the second solenoid valve (27).

2. The carbon potential detection device for a multi-purpose carburizing furnace according to claim 1, characterized in that: A motor (2) is fixedly connected to the mounting plate (1). A transmission shaft (3) is coaxially fixed to the output shaft of the motor (2). The transmission shaft (3) is rotatably connected to the mounting plate (1) through a sealing slip ring. The transmission shaft (3) passes into the furnace body and is coaxially fixed to a first bevel gear (4). The first bevel gear (4) meshes with a second bevel gear (5). The second bevel gear (5) is coaxially fixed to one end of a rotating shaft (7). The rotating shaft (7) is rotatably connected to the mounting plate (1) through a bracket (8). A fan blade (6) is fixedly installed at the other end of the rotating shaft (7). The fan blade (6) is correspondingly set to the detection end of the oxygen probe (12).

3. The carbon potential detection device for a multi-purpose carburizing furnace according to claim 1, characterized in that: A calibration tube (13) is fixedly attached to the mounting plate (1). The calibration tube (13) is L-shaped and has one end facing downward inside the furnace. A gravity sensor (17) is detachably connected to one end of the calibration tube (13) that extends out of the furnace. The gravity sensor (17) and the calibration tube (13) are sealed together. A pull rope (14) is connected to the measuring end of the gravity sensor (17). The pull rope (14) is threaded through the calibration tube (13). The other end of the pull rope (14) extends out of the calibration tube (13) and is fixedly attached to a test piece (15). The maximum width of the test piece (15) is smaller than the inner diameter of the calibration tube (13).

4. The carbon potential detection device for a multi-purpose carburizing furnace according to claim 2, characterized in that: The outlet of the second gas supply pipe is connected to the inlet of a three-way valve (28). The outlet of the three-way valve (28) is connected to the inlet of the oxygen probe (12) and the purge pipe (11). The purge pipe (11) extends into the furnace body and is connected to a purge ring (29). The purge ring (29) is loosely fitted on the outside of the oxygen probe (12) and is set corresponding to the detection end of the oxygen probe (12).

5. The carbon potential detection device for a multi-purpose carburizing furnace according to claim 1, characterized in that: The air inlet of the first air pump (20) is connected to a filter (19), which is located inside the outer casing (18).

6. The carbon potential detection device for a multi-purpose carburizing furnace according to claim 5, characterized in that: The filter (19) includes a housing (1901), one end of which is connected to an air inlet pipe (1902), the air inlet pipe (1902) extending out of the outer casing (18), and the other end of the housing (1901) being connected to the air inlet of the first air pump (20) via an air outlet pipe (1903). The outer shell (1901) is provided with a filter layer (1904), a first adsorption layer (1905) and a second adsorption layer (1906) arranged sequentially along the gas flow direction.

7. The carbon potential detection device for a multi-purpose carburizing furnace according to claim 1, characterized in that: A pressure sensor (24) is installed inside the gas storage chamber.

8. The carbon potential detection device for a multi-purpose carburizing furnace according to claim 1, characterized in that: The outer casing (18) is equipped with a multi-gas measurement sensor (9), the measuring end of which extends into the furnace body.

9. A carbon potential detection device for a multi-purpose carburizing furnace according to claim 1, characterized in that: A temperature sensor (10) is installed inside the outer casing (18). The measuring end of the temperature sensor (10) extends into the furnace body and is close to the detection end of the oxygen probe (12).

10. A carbon potential detection device for a multi-purpose carburizing furnace according to claim 3, characterized in that: A pulley (16) is installed inside the calibration tube (13). The axis of the pulley (16) is set horizontally, and the pull rope (14) is in rolling contact with the pulley (16).

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