An on-line iron powder content detection device and method

Abstract

The present invention discloses an on-line iron powder content detection device and method. The on-line iron powder content detection device includes an on-line measurement module, a filtering and amplifying module, a control module, a communication module, and a calculation module. The on-line measurement module is used to adsorb iron powder and output a detection signal according to the situation of adsorbed iron powder. The control module is used to control the operation of the on-line measurement module and obtain the detection signal, and control the communication module and the filtering and amplifying module to work. The filtering and amplifying module is used to remove noise and amplify the detection signal. The communication module is used to send the processed detection signal to the calculation module for calculating the iron powder concentration. The present invention can realize the on-line measurement of the iron powder concentration, and can also solve the problem in the prior art that only off-line manual detection can be carried out, and it is difficult to realize large-scale and rapid detection.

Description

Technical Field

[0001] The present invention relates to the field of industrial robots, and particularly to an on-line iron powder content detection device and method. Background Art

[0002] In the field of industrial robots, the speed reducer is one of its core components, and its performance directly affects the stability and reliability of the robot. During the operation of the speed reducer, wear occurs due to the meshing between gears and the rolling of rolling elements in the bearings, forming iron filings (powder), and these iron filings are carried away by lubricating oil or grease. At present, a common method for judging whether the lubricating oil of an industrial robot speed reducer needs to be replaced and the degree of aging of the speed reducer is to detect the iron powder concentration in the lubricating oil or grease. However, the existing iron powder concentration detection methods have the following deficiencies:

[0003] Firstly, the existing detection methods usually require sampling during robot shutdown maintenance, which not only increases production costs but also causes production interruption and affects production efficiency. Secondly, the detection cycle usually needs to be arranged according to the production plan, which may lead to too long a detection cycle and unable to timely reflect the actual wear state of the speed reducer, thus delaying the maintenance time and increasing the risk of equipment failure. In addition, the existing detection methods usually require the use of external special iron powder concentration detection instruments, that is, mainly rely on off-line manual detection methods, which not only increases the equipment investment cost but also increases the operation complexity. When detecting a large number of iron powder concentrations within a limited time, it takes a lot of time, manpower and material resources, thus bringing a heavy burden. Therefore, how to realize the on-line measurement of iron powder concentration during robot operation, avoid shutdown sampling, and reduce detection time and costs has become an urgent technical problem to be solved. Summary of the Invention

[0004] The purpose of the present invention is to provide an on-line iron powder content detection device and method, which can realize the on-line measurement of iron powder concentration and can also solve the problem that only off-line manual detection can be carried out in the prior art and it is difficult to realize large-scale rapid detection.

[0005] To solve the above technical problems, the present invention provides an on-line iron powder content detection device, including an on-line measurement module, a filtering and amplifying module, a control module, a communication module and a calculation module;

[0006] The on-line measurement module is used for adsorbing iron powder and outputting a detection signal according to the situation of adsorbed iron powder;

[0007] The control module is used for controlling the operation of the on-line measurement module and obtaining the detection signal, and controlling the communication module and the filtering and amplifying module to work;

[0008] The filtering and amplifying module is used to remove noise and amplify the detection signal of the on-line measurement module;

[0009] The communication module is used to send the processed detection signal to the calculation module for calculating the iron powder concentration.

[0010] Further, the on-line measurement module includes a connecting rod, and a first conductive component and a second conductive component that form a parallel plate capacitor;

[0011] A magnetic conductive layer is provided on one side of the first conductive component close to the second conductive component for adsorbing iron powder;

[0012] The connecting rod is fixedly connected to the first conductive component; a predetermined distance is reserved between the first conductive component and the second conductive component.

[0013] Further, a non-magnetic corrosion-resistant metal layer is provided on one side of the first conductive component away from the second conductive component.

[0014] Further, the on-line measurement module includes a magnet bar, an upper clamping rod and a lower clamping rod;

[0015] Both ends of the magnet bar are respectively connected to the upper clamping rod and the lower clamping rod.

[0016] Further, it further includes a housing and a power supply module; the outer side wall of the housing is provided with threads; the filtering and amplifying module, the control module, the power supply module and the communication module are all located inside the housing; the on-line measurement module is arranged at the end of the housing and can extend into the grease area inside the reducer gearbox; the power supply module is connected to the on-line measurement module, the communication module, the filtering and amplifying module and the control module; the control module is further used to monitor the power of the power supply module.

[0017] In addition, the present invention also proposes an on-line iron powder content detection method, which uses the on-line iron powder content detection device as described above, and specifically includes the following:

[0018] Record the initial detection signal value of the on-line measurement module;

[0019] When the reducer is running, use the on-line measurement module to adsorb iron powder and obtain the current detection signal value;

[0020] Calculate the iron powder concentration according to the difference between the initial detection signal value and the current detection signal value.

[0021] Further, it further includes:

[0022] For the online measurement module with a parallel-plate capacitor structure, the capacitance value is calculated according to the parallel-plate capacitance formula C = εS / d, where ε is the dielectric constant of the medium between the plates, with the unit of F / m, S is the facing area of the two plates, with the unit of m 2 , and d is the distance between the two plates, with the unit of m;

[0023] The change in capacitance value is obtained by detecting the change in the d value, where the decrease in the d value is the thickness of the adsorbed iron powder;

[0024] Under the experimental environment, iron powder is added for calibration, and the particle size of the iron powder is determined according to the particle diameter generated by the actual wear of the reducer;

[0025] Record the initial capacitance value C0 before adding iron powder, the capacitance value C1 after adding iron powder, calculate the capacitance value difference ΔC = C1 - C0, establish the corresponding relationship curve between the capacitance value difference ΔC and the iron powder concentration, and the corresponding relationship curve satisfies the functional relationship of c' = aX + b, where c' is the iron powder concentration, X is the capacitance value difference ΔC, a is the proportionality coefficient, and b is the calibration deviation value; calculate the iron powder concentration c'.

[0026] Furthermore, it also includes:

[0027] For the online measurement module with a magnet bar structure, record the initial conductivity of the magnet bar in the initial state;

[0028] The power supply module applies a voltage to both ends of the magnet bar for several seconds; measure the current value flowing through the magnet bar to obtain the initial current value;

[0029] At preset time intervals, apply the same voltage to both ends of the magnet bar. After iron powder is adsorbed on the surface of the magnet bar, the conductivity of the magnet bar changes, causing a change in the current value, and then measure the current value at present;

[0030] Under the experimental environment, iron powder is added for calibration, and the particle size of the iron powder is determined according to the particle diameter generated by the actual wear of the reducer; record the initial current value I0 before adding iron powder, the current value I after adding iron powder, and calculate the current value difference ΔI = I - I0; by measuring the current values under different iron powder content conditions, obtain the corresponding data between the current value difference and the iron powder content, and perform fitting to obtain the corresponding relationship function between the current value difference and the iron powder concentration;

[0031] According to the difference between the current value at present and the initial current value, combined with the pre-calibrated corresponding relationship function between the current difference and the iron powder concentration, calculate the current iron powder concentration.

[0032] Further, it further includes: filtering and denoising the detection signal; amplifying the processed signal; sending the amplified signal to the calculation module through the communication module; and giving an alarm prompt according to a preset iron powder concentration threshold.

[0033] Further, the step of sending the amplified signal to the calculation module through the communication module specifically includes: recording the time and iron powder concentration value of each detection; plotting a trend graph of the iron powder concentration changing with time; judging the wear degree of the reducer and whether to replace the lubricating oil according to the trend graph and the set standard; and giving a maintenance reminder when the iron powder concentration exceeds the preset threshold.

[0034] By the above technical solution, the present invention has the following beneficial effects:

[0035] Through the settings of the online measurement module, filtering and amplifying module, control module, communication module and calculation module; and the online measurement module is used to adsorb iron powder and output a detection signal according to the situation of adsorbed iron powder; the control module is used to control the operation of the online measurement module and obtain the detection signal, and control the communication module and the filtering and amplifying module to work; the filtering and amplifying module is used to remove noise and amplify the detection signal; the communication module is used to send the processed detection signal to the calculation module for calculating the iron powder concentration. The present invention can realize the online measurement of the iron powder concentration, avoid shutdown sampling, and reduce the detection time and cost.

[0036] In addition, by establishing a corresponding relationship curve between the capacitance value difference and the iron powder concentration, or a corresponding relationship curve between the current difference and the iron powder concentration, the present invention can automatically and frequently monitor the change of the iron powder concentration online, and give a maintenance reminder when it exceeds the preset threshold, so as to improve the equipment maintenance efficiency and extend the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the overall structure of the online iron powder content detection device in an embodiment of the present invention;

[0038] Figure 2 It is a schematic diagram of the overall structure of the online iron powder content detection device in another embodiment of the present invention;

[0039] Figure 3 It is a flowchart of the online iron powder content detection method in an embodiment of the present invention.

[0040] In the figure, 11, the first conductive component; 12, the second conductive component; 13, the connecting rod; 101, the magnet bar; 102, the upper clamping rod; 103, the lower clamping rod;

[0041] 2, the filtering and amplifying module; 3, the power supply module; 4, the communication module; 5, the housing; 6, the grease area inside the gearbox; 7, the control module. Detailed implementation manners

[0042] The following will describe an on-line iron powder content detection device and method of the present invention in more detail with reference to the accompanying drawings, in which the preferred embodiments of the present invention are shown. It should be understood that those skilled in the art can modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as broad knowledge for those skilled in the art and not as a limitation to the present invention.

[0043] In the following paragraphs, the present invention will be described more specifically by way of example with reference to the accompanying drawings. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are all in a very simplified form and use non-precise scales, only for the purpose of facilitating and clearly assisting in explaining the purpose of the embodiments of the present invention.

[0044] As Figure 1 - Figure 2 shown, an embodiment of the present invention provides a convenient and practical on-line iron powder content detection device, including an on-line measurement module, a filtering and amplifying module 2, a control module 7, a power supply module 3, a communication module 4, and a calculation module (not shown in the figure for the sake of simplicity of illustration).

[0045] Specifically, the on-line measurement module is used to adsorb iron powder and output a detection signal according to the situation of adsorbed iron powder; the control module 7 is used to control the operation of the on-line measurement module and obtain the detection signal, control the communication module 4 and the filtering and amplifying module 2 to work, and monitor the power of the power supply module 3; the filtering and amplifying module 2 is used to remove noise and amplify the detection signal of the on-line measurement module; the power supply module 3 is connected to the on-line measurement module, the communication module 4, the filtering and amplifying module 2, and the control module 7; the communication module 4 is used to send the processed detection signal to the calculation module for calculating the iron powder concentration. Among them, the control module 7 controls the operation of the on-line measurement module, specifically referring to controlling the on-line measurement module to be powered on for a period of time (for example, continuously for several seconds) for detection.

[0046] In one embodiment, the structure of the on-line measurement module can take various forms, such as a parallel-plate capacitor structure or a magnet bar 101 structure, to adapt to different detection requirements and environmental conditions. The filtering and amplifying module 2 is responsible for removing noise and amplifying the detection signal obtained by the on-line measurement module to improve the accuracy and reliability of the signal and enhance the stability of the detection result. The control module 7 not only controls the operation of the on-line measurement module to obtain accurate detection signals, but also controls the communication module 4 to perform a sending action, timely sending the processed detection signals to the calculation module for iron powder concentration calculation. At the same time, it monitors the power of the power supply module 3 to ensure the continuous and stable operation of the device. The power supply module 3 can provide stable power support for the entire device, expanding the applicable range and working duration of the device. The communication module 4 can adopt wireless communication technologies, such as low-power consumption protocols like zigbee and Lora, to send the processed detection signals to the calculation module, facilitating remote monitoring and data transmission and improving the convenience and real-time performance of detection. The calculation module receives the detection signals sent by the communication module 4 and can calculate the iron powder concentration according to the preset algorithms and models, providing accurate detection results and a basis for subsequent processing for users.

[0047] In this embodiment, the control module 7 not only controls the operation of the on-line measurement module, but also is responsible for controlling the working timing of the filtering and amplifying module 2. Specifically, the control module 7 controls the filtering and amplifying module 2 to perform signal processing within the detection period and does not provide power supply outside the detection period, thereby optimizing the energy usage of the power supply module 3, extending the battery life, and reducing the frequency of battery replacement.

[0048] Through the collaborative work of each module in this embodiment, it is possible to achieve rapid and accurate detection of the iron powder content, and also improve the detection efficiency and the reliability of the results.

[0049] In a specific embodiment, continue to refer to Figure 1 As shown, the on-line measurement module adopts a parallel-plate capacitor structure. Specifically, the on-line measurement module includes a connecting rod 13 and a first conductive component 11 and a second conductive component 12 that form a parallel-plate capacitor, that is, the first conductive component 11 and the second conductive component 12 are arranged opposite to each other;

[0050] More specifically, a magnetic conductive layer is provided on the side of the first conductive member 11 close to the second conductive member 12 for adsorbing iron powder. The magnetic conductive layer is made of a corrosion-resistant conductive metal and has strong magnetism, which can effectively adsorb iron powder, thereby improving the sensitivity and accuracy of detection. The first conductive member 11 and the second conductive member 12 are respectively connected to the positive and negative electrodes of the power supply module 3 through a first connecting wire (such as a wire). The connecting rod 13 is fixedly connected to the first conductive member 11. The first conductive member 11 and the second conductive member 12 are arranged opposite to each other with a predetermined distance reserved. As the iron powder is continuously adsorbed by the magnetic conductive layer of the first conductive member 11, the actual distance d value gradually decreases, thereby causing a change in the capacitance value. This fixed structure design is simple and reliable, without moving parts, reducing the failure points and improving the stability and reliability of the device.

[0051] In addition, this embodiment further includes a housing 5. Specifically, the outer side wall of the housing 5 is provided with threads, which is convenient for installing the device at the oil outlet position of the reducer gearbox, replacing the original sealing screw, and achieving close contact with the grease area 6 inside the gearbox. Further, the filtering and amplifying module 2, the control module 7, the power supply module 3, and the communication module 4 are all located inside the housing 5. The on-line measurement module is arranged at the end of the housing 5 and can extend into the grease area 6 inside the reducer gearbox, directly contact the lubricating oil / grease, adsorb iron powder, and obtain accurate detection signals. The device structure of this embodiment is reasonably designed and easy to install, which can effectively improve the accuracy and convenience of detection, and enhance the practicability and reliability of the device.

[0052] Preferably, both the first conductive member 11 and the second conductive member 12 are conductive metal discs. A non-magnetic corrosion-resistant layer is provided on the side of the first conductive member 11 away from the second conductive member 12. The first conductive member 11 is disc-shaped, and a magnetic corrosion-resistant metal layer is provided on the side of the first conductive member 11 close to the second conductive member 12. The second conductive member 12 is a non-magnetic conductive metal disc. The centers of the first conductive member 11 and the second conductive member 12 are aligned.

[0053] In this embodiment, a non-magnetic corrosion-resistant metal layer is provided on the side of the first conductive member 11 away from the second conductive member 12. This metal layer has the function of reducing or shielding magnetism, enabling the side of the first conductive member 11 close to the second conductive member 12 to adsorb more iron powder and improving the measurement accuracy. At the same time, the corrosion-resistant metal layer can prevent the chemical substances in the lubricating grease from eroding the detection device and avoid impurities from mixing into the lubricating oil, resulting in the deterioration of the lubricating oil. In addition, the structural design with metal layers on both sides of the first conductive member 11 improves the overall strength and is not easily damaged.

[0054] In another specific embodiment, with continued reference to Figure 2 As shown, the on-line measurement module may also adopt the structure of a magnet bar 101. Specifically, the on-line measurement module includes a magnet bar 101, an upper clamping rod 102, and a lower clamping rod 103.

[0055] More specifically, both ends of the magnet bar 101 are respectively connected to the upper clamping rod 102 and the lower clamping rod 103; the upper clamping rod 102 and the lower clamping rod 103 are respectively connected to the positive electrode and the negative electrode of the power supply module 3 through a second connecting wire (such as a wire).

[0056] In this embodiment, the magnet bar 101 is made of a material with strong magnetism, such as a ferrite magnet, which has poor electrical conductivity but can effectively adsorb iron powder. The upper clamping rod 102 and the lower clamping rod 103 are respectively connected to both ends of the magnet bar 101 to form a stable structure. The upper clamping rod 102 and the lower clamping rod 103 are respectively connected to the positive electrode and the negative electrode of the power supply module 3 through a second connecting wire to provide electrical energy for the magnet bar 101. This on-line measurement module with the structure of the magnet bar 101 uses the strong magnetism of the magnet bar 101 to adsorb iron powder. As more and more adsorbed iron powder covers the surface of the magnet bar, the electrical conductivity continuously increases. By detecting the change in the electrical conductivity of the magnet bar 101 to obtain a detection signal, it has the advantages of simple structure and low cost, is applicable to various detection environments and conditions, and enhances the applicability and flexibility of the device.

[0057] In addition, this embodiment further includes a housing 5. Specifically, the outer side wall of the housing 5 is provided with threads, which is convenient for installing the device at the oil outlet position of the reducer gearbox, replacing the original sealing screw, and achieving close contact with the grease area 6 inside the gearbox. Further, the filter amplification module 2, the control module 7, the power supply module 3, and the communication module 4 are all located inside the housing 5; the on-line measurement module is arranged at the end of the housing 5 and can extend into the grease area 6 inside the reducer gearbox to directly contact the lubricating oil / grease, adsorb iron powder, and obtain an accurate detection signal. The device structure of this embodiment is reasonably designed and easy to install, which can effectively improve the accuracy and convenience of detection, and enhance the practicability and reliability of the device.

[0058] In addition, as Figure 3 shown, this embodiment also proposes an on-line iron powder content detection method, which uses the on-line iron powder content detection device as described above, and specifically includes the following steps:

[0059] S1. Record the initial detection signal value of the on-line measurement module;

[0060] S2. When the reducer is running, use the on-line measurement module to adsorb iron powder and obtain the current detection signal value;

[0061] S3. Calculate the iron powder concentration based on the difference between the initial detection signal value and the current detection signal value.

[0062] In a specific example, this embodiment further includes: for the on-line measurement module adopting a flat capacitor structure, calculate the capacitance value according to the flat capacitor formula C = εS / d, and the unit is F (farad). Wherein, ε is the dielectric constant of the medium between the flat plates (i.e., the first conductive member 11 and the second conductive member 12), and the unit is F / m; S is the facing area of the two flat plates (i.e., the first conductive member 11 and the second conductive member 12), and the unit is m 2 , since the two flat plates are fixedly aligned, this value remains unchanged; d is the distance between the two flat plates (i.e., the first conductive member 11 and the second conductive member 12), and the unit is m. As the iron powder is adsorbed by the magnetic conductive layer of the first conductive member 11, there are two main influencing factors: one is that the value of d decreases, that is, the effective distance between the two flat plates decreases; the other is that the accumulation of iron powder between the flat plates may have a slight impact on the dielectric constant ε of the medium. This device mainly uses the capacitance change caused by the change of the d value as the measurement basis, because the magnetic conductive layer will preferentially adsorb the iron powder and make it concentrate on the surface of the first conductive member 11, so that the change of the d value becomes the dominant factor. During the calibration process, the corresponding relationship curve between the capacitance value difference ΔC and the iron powder concentration established through experiments has comprehensively considered the combined effects of these two factors.

[0063] In this embodiment, under the experimental environment, add iron powder for calibration, and the particle size of the iron powder is determined according to the particle diameter generated by the actual wear of the reducer; record the capacitance value difference ΔC after each addition, obtain the corresponding data between the capacitance value difference ΔC and the iron powder content, and perform fitting to obtain the corresponding relationship function between the capacitance value difference ΔC and the iron powder concentration. More specifically, record the initial capacitance value C0 before adding iron powder, the capacitance value C1 after adding iron powder, calculate the capacitance value difference ΔC = C1 - C0, establish the corresponding relationship curve between the capacitance value difference ΔC and the iron powder concentration, and the corresponding relationship curve satisfies the function relationship of c' = aX + b, where c' is the iron powder concentration, X is the capacitance value difference ΔC, a is the proportional coefficient, and b is the calibration deviation value; calculate the iron powder concentration c'.

[0064] Among them, during calibration, the lubricating oil of a brand-new robot reducer is required, and the temperature and pressure of the experimental environment are adjusted to conditions similar to those of the actual reducer working environment. The working state of the gearbox is simulated by stirring the lubricating oil. By analyzing the wear particles of the actually operating reducer, the particle size range of the iron powder for the experiment is determined to be 10 μm to 100 μm. Different masses of iron powder with a specific particle size are gradually added to the lubricating oil, and the capacitance value is measured at each iron powder content. Based on the capacitance value of the pure lubricating oil, the capacitance value difference ΔC corresponding to different iron powder contents is calculated. Through fitting these experimental data, a relationship function between the capacitance value difference ΔC and the iron powder content is established.

[0065] For example, in the experimental environment, using the same type of new oil / grease and operating environment (temperature and pressure), the following calibration is carried out: record the initial capacitance value C0 when there is no iron powder, and gradually add iron powder. The particle size of the iron powder is determined according to the particle diameter of the wear particles generated by the actual reducer (that is, iron powder similar to the particle size of the wear particles generated by the actual gearbox, such as iron powder of 10 μm to 100 μm); record the capacitance value C1 and the corresponding iron powder concentration c' (which can be measured using a third-party instrument) after each addition; calculate the capacitance difference ΔC = C1 - C0; establish a corresponding relationship curve between the capacitance value difference ΔC and the iron powder concentration. The corresponding relationship curve satisfies the functional relationship of c' = aX + b, where c' is the iron powder concentration, X is the capacitance value difference ΔC, a is the proportionality coefficient (i.e., the main proportional relationship coefficient), and b is the calibration deviation value (i.e., the deviation value for calibration).

[0066] In this embodiment, a corresponding relationship curve between the capacitance value difference ΔC and the iron powder concentration is established through experiments, providing an accurate calculation basis for actual detection, improving the accuracy and reliability of detection, and enhancing the detection ability of the device. In addition, for the same model of lubricating oil and reducer, only one such calibration operation needs to be performed. During subsequent use, only the detected ΔC value needs to be substituted into the calibration formula to obtain the current iron powder concentration. This embodiment establishes a calibration curve through experiments, providing an accurate calculation basis for actual detection and improving the accuracy and reliability of detection.

[0067] In another specific example, this embodiment further includes: for the online measurement module adopting the structure of the magnet bar 101, record the initial conductivity of the magnet bar 101 in the initial state; the power supply module 3 applies a voltage lasting for several seconds across the two ends of the magnet bar 101; measure the current value flowing through the magnet bar 101 to obtain the initial current value; at preset time intervals, apply the same voltage across the two ends of the magnet bar 101. After iron powder is adsorbed on the surface of the magnet bar, the conductivity of the magnet bar changes, causing a change in the current value, and then measure the current value at present. Under the experimental environment, iron powder is added for calibration, and the particle size of the iron powder is determined according to the particle diameter generated by the actual wear of the reducer; record the initial current value I0 before adding the iron powder and the current value I after adding the iron powder, and calculate the current value difference ΔI = I - I0; by measuring the current values under different iron powder content conditions, obtain the corresponding data of the current value difference and the iron powder content, and perform fitting to obtain the corresponding relationship function between the current value difference and the iron powder concentration; according to the difference between the current value at present and the initial current value, and in combination with the corresponding relationship function between the pre-calibrated current difference and the iron powder concentration, calculate the current iron powder concentration.

[0068] Among them, the magnet bar itself has a certain conductivity. After iron powder is adsorbed on its surface, due to the conductivity of the iron powder, the overall conductivity of the magnet bar is enhanced, resulting in an increase in the measured current value. According to the difference between the current value at present and the initial current value, and in combination with the corresponding relationship function between the pre-calibrated current difference and the iron powder concentration, calculate the current iron powder concentration.

[0069] In this embodiment, as the iron powder accumulates on the surface of the magnet bar 101, the conductivity of the magnet bar 101 gradually increases, and the current value flowing through the magnet bar 101 will also increase accordingly. According to the difference between the current value at present and the initial current value, and in combination with the pre-calibrated corresponding relationship curve between the current difference and the iron powder concentration, calculate the current iron powder concentration. This embodiment uses the change in the conductivity of the magnet bar 101 to detect the iron powder concentration, and has the advantages of simple structure, low cost, etc., is applicable to a variety of detection environments and conditions, and enhances the applicability and flexibility of the device.

[0070] In one embodiment, for example, in the initial state, record the resistance R0 of the magnet bar 101 by applying a known voltage V0 across the two ends of the magnet bar 101 and measuring the flowing current I0, and use Ohm's law R0 = V0 / I0. Apply a voltage V lasting for several seconds across the two ends of the magnet bar 101 and measure the initial current I0. After a preset time interval, apply the same voltage V across the two ends of the magnet bar 101 again and measure the current I flowing through the magnet bar 101. Calculate the change in current ∆I = I - I0.

[0071] Calculate the current iron powder concentration according to the pre-calibrated correspondence curve between the current difference ∆I and the iron powder concentration C. This relationship can be obtained through experiments. For example, by gradually increasing the iron powder in a controlled environment and measuring the corresponding current changes. In the experiment, iron powder is gradually added around the magnet bar 101. The particle size of the iron powder is determined according to the particle diameter generated by the actual wear of the reducer (i.e., iron powder with a particle size similar to that generated by the actual wear of the gearbox, such as iron powder with a particle size of 10μm - 100μm). After each addition of iron powder, measure the current I and calculate ∆I. Using these data points, establish the functional relationship between ∆I and the iron powder concentration c', such as the linear relationship c' = a∆I + b, where a and b are parameters obtained through data fitting.

[0072] Preferably, this embodiment further includes: performing filtering and denoising processing on the detection signal to remove noise interference in the signal and improve the accuracy and reliability of the signal; amplifying the processed signal to enhance the amplitude of the signal for subsequent detection and calculation; sending the amplified signal to the calculation module through the communication module 4; performing alarm prompts according to a preset iron powder concentration threshold. When the iron powder concentration exceeds the preset threshold, send a maintenance reminder to prompt the user to perform maintenance and processing in a timely manner.

[0073] Further, the step of sending the amplified signal to the calculation module through the communication module 4 specifically includes: recording the time and iron powder concentration value of each detection to form a complete detection data record; plotting a trend graph of the iron powder concentration changing with time. Through the trend graph, the change of the iron powder concentration can be intuitively observed, providing a basis for subsequent analysis and prediction; judging the wear degree of the reducer and whether to replace the lubricating oil according to the trend graph and the set standard; when the iron powder concentration exceeds the preset threshold, send a maintenance reminder.

[0074] In this embodiment, taking the online measurement module with a flat capacitor structure as an example, for instance, ε = 4×8.854187817×10 −12 F / m (i.e., ε = ε r ε0, the relative permittivity ε r is generally between 2 - 5. For example, take 4, and then multiply by the vacuum permittivity ε0 = 8.854187817×10 −12 F / m ≈ 8.854×10 −12 F / m); S takes the ordinary oil outlet sealing screw G3 / 4 as an example (the inner diameter is about 24mm, for example), and the circular flat plate area is 452×10 -6 m 2 ; d takes 5×10 -3 m (i.e., the initial predetermined distance is set to 5×10 -3m, as the iron powder accumulates, the actual distance will gradually decrease), C≈3.2 pF can be obtained. The specific calculation process is as follows: According to the parallel-plate capacitance formula C = εS / d to calculate the capacitance value, then C = (4×8.854×10 −12 ×452×10 -6 ) / (5×10 -3 )≈3.2×10 −12 F = 3.2 pF. That is, initially C0 = 3.2 pF. After the iron powder accumulates, it is measured that: C1 = 3.5 pF, then: ΔC = C1 - C0 = 3.5 pF - 3.2 pF = 0.3 pF. This initial capacitance value (C = 3.2 pF) is used as the reference value C0 of the device. The iron powder concentration c' = 5 ppm / pF×0.3 pF = 1.5 ppm can be calculated. In this way, the real-time monitoring of the iron powder concentration in the lubricating oil can be realized.

[0075] Therefore, when the iron powder gradually accumulates on the surface of the first conductive component 11, the value of d will gradually decrease, resulting in an increase in the actual capacitance value C1. By calculating the change in capacitance value ΔC (i.e., C1 - C0), the degree of iron powder accumulation can be reflected, so that the monitoring of the iron powder content in the lubricating oil can be realized, and it can also be monitored at set time intervals. Since the change in iron powder concentration is slow, the set time interval can be set according to the actual situation, such as 1 hour or more.

[0076] In addition, taking the online measurement module using the structure of the magnet bar 101 as an example, since the ferrite material (ceramic material) has poor conductivity, the initial current I0 is very small. For example, for a ferrite magnet bar with a length of 10 mm and a diameter of 2 mm, its resistance value is about 3.18 MΩ at room temperature and about 3.26 MΩ at the operating temperature of the reducer (about 50°C). When a voltage of 2 V is applied across both ends, the initial current I0 is about 0.61 μA (when there is no iron powder). When there is iron powder adsorbed on the surface of the magnet bar 101, for example, the measured current I = 0.8 μA. Calculate the current difference: ΔI = I - I0 = 0.8 μA - 0.61 μA = 0.19 μA. If the corresponding relationship obtained through experiments is c' = 2.5ΔI + 0: c' = 2.5 ppm / μA×0.19 μA = 0.475 ppm. In this way, by measuring the change in the tiny current, the iron powder concentration c' adsorbed on the magnet bar 101 can be accurately inferred.

[0077] In summary, an online iron powder content detection device and method proposed by the present invention have the following advantages:

[0078] Through the settings of an online measurement module, a filtering and amplification module, a control module, a communication module, and a calculation module; and the online measurement module is used to adsorb iron powder and output a detection signal according to the situation of the adsorbed iron powder; the control module is used to control the operation of the online measurement module and obtain the detection signal, and control the communication module and the filtering and amplification module to work; the filtering and amplification module is used to remove noise and amplify the detection signal; the communication module is used to send the processed detection signal to the calculation module for calculating the iron powder concentration. The present invention can realize the online measurement of the iron powder concentration, avoid shutdown sampling, and reduce the detection time and cost.

[0079] In addition, by establishing a corresponding relationship curve between the capacitance value difference and the iron powder concentration, or a corresponding relationship curve between the current difference and the iron powder concentration, the present invention can automatically and frequently monitor the change of the iron powder concentration online and issue a maintenance reminder when it exceeds a preset threshold, thereby improving the equipment maintenance efficiency and extending the service life of the equipment.

[0080] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and its equivalent technologies, the present invention also intends to include these changes and modifications.

Claims

1. An on-line iron powder content detection device, characterized in that, It includes an online measurement module, a filtering and amplifying module, a control module, a communication module, and a calculation module; The online measurement module is used to adsorb iron powder and output a detection signal according to the situation of the adsorbed iron powder; The online measurement module includes a connecting rod, a first conductive component, and a second conductive component that form a parallel-plate capacitor; the connecting rod is fixedly connected to the first conductive component; on one side of the first conductive component close to the second conductive component, there is a magnetic conductive layer for adsorbing iron powder; on the side of the first conductive component away from the second conductive component, there is a non-magnetic corrosion-resistant metal layer; the first conductive component is a conductive metal disc; the second conductive component is a non-magnetic conductive metal disc; the centers of the first conductive component and the second conductive component are aligned; the first conductive component and the second conductive component are arranged opposite to each other and maintain a predetermined distance, and the predetermined distance changes with the amount of adsorbed iron powder; therefore, as the iron powder is continuously adsorbed by the magnetic conductive layer of the first conductive component, the actual distance d value gradually decreases, resulting in a change in the capacitance value; Alternatively, the online measurement module includes a magnet bar, an upper clamping rod, and a lower clamping rod; the two ends of the magnet bar are respectively connected to the upper clamping rod and the lower clamping rod; The control module is used to control the operation of the online measurement module and obtain the detection signal, and control the communication module and the filtering and amplifying module to work; The filtering and amplifying module is used to remove noise and amplify the detection signal; The communication module is used to send the processed detection signal to the calculation module for iron powder concentration calculation; It further includes a housing; the outer side wall of the housing is provided with threads, which is convenient to install the online iron powder content detection device at the oil outlet position of the reducer gearbox, replace the original sealing screw, and achieve close contact with the grease area inside the gearbox; the online measurement module is arranged at the end of the housing and can extend into the grease area inside the reducer gearbox to directly contact the lubricating oil / grease and adsorb iron powder.

2. The on-line iron powder content detection device according to claim 1, wherein It further includes a power supply module; the filtering and amplifying module, the control module, the power supply module, and the communication module are all located inside the housing; the online measurement module is arranged at the end of the housing and can extend into the grease area inside the reducer gearbox; the power supply module is connected to the online measurement module, the communication module, the filtering and amplifying module, and the control module; the control module is also used to monitor the power of the power supply module.

3. An on-line iron powder content detection method, which uses the on-line iron powder content detection device described in any one of claims 1-2, and is characterized in that, Specifically, it includes the following: Record the initial detection signal value of the online measurement module; When the reducer is running, use the online measurement module to adsorb iron powder and obtain the current detection signal value; Calculate the iron powder concentration according to the difference between the initial detection signal value and the current detection signal value.

4. The on-line iron powder content detection method according to claim 3, wherein It further includes: For the online measurement module adopting a parallel plate capacitor structure, the capacitance value is calculated according to the parallel plate capacitance formula C = εS / d, where ε is the dielectric constant of the medium between the parallel plates, with the unit of F / m, S is the facing area of the two parallel plates, with the unit of m 2 , and d is the distance between the two parallel plates, with the unit of m; Obtain the change in capacitance value by detecting the change in the d value, where the decrease in the d value is the thickness of the adsorbed iron powder; Under the experimental environment, add iron powder for calibration, and the particle size of the iron powder is determined according to the particle diameter generated by the actual wear of the reducer; Record the initial capacitance value C0 before adding iron powder, the capacitance value C1 after adding iron powder, calculate the capacitance difference ΔC = C1 - C0, establish a corresponding relationship curve between the capacitance difference ΔC and the iron powder concentration, and the corresponding relationship curve satisfies the functional relationship of c' = aX + b, where c' is the iron powder concentration, X is the capacitance difference ΔC, a is the proportionality coefficient, and b is the calibration deviation value; calculate the iron powder concentration c'.

5. The online iron powder content detection method according to claim 3, characterized in that It further includes: For the online measurement module using the magnet bar structure, record the initial conductivity of the magnet bar in the initial state; The power supply module applies a voltage to both ends of the magnet bar for several seconds; measure the current value flowing through the magnet bar to obtain the initial current value; At preset time intervals, apply the same voltage to both ends of the magnet bar. After iron powder is adsorbed on the surface of the magnet bar, the conductivity of the magnet bar changes, causing a change in the current value, and then measure the current value at present; Under the experimental environment, add iron powder for calibration, and the particle size of the iron powder is determined according to the particle diameter generated by the actual wear of the reducer; record the initial current value I0 before adding iron powder, the current value I after adding iron powder, and calculate the current difference ΔI = I - I0; obtain the corresponding data between the current difference and the iron powder content by measuring the current values under different iron powder content conditions, and perform fitting to obtain the corresponding relationship function between the current difference and the iron powder concentration; According to the difference between the current value at present and the initial current value, and in combination with the corresponding relationship function between the pre-calibrated current difference and the iron powder concentration, calculate the current iron powder concentration.

6. The on-line iron powder content detection method according to claim 3, characterized in that, It further includes: performing filtering and denoising processing on the detection signal; amplifying the processed signal; sending the amplified signal to the calculation module through the communication module; performing alarm prompts according to the preset iron powder concentration threshold.

7. The online iron powder content detection method according to claim 6, characterized in that The step of sending the amplified signal to the calculation module through the communication module specifically includes: recording the time and iron powder concentration value of each detection; plotting a trend graph of the iron powder concentration changing with time; judging the wear degree of the reducer and whether to change the lubricating oil according to the trend graph and in accordance with the set standard; when the iron powder concentration exceeds the preset threshold, send a maintenance reminder.

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