Self-adaptive variable-frequency flapping sweeping system and control method

Abstract

The invention relates to a self-adaptive variable-frequency flapping sweeping system and a control method thereof. The device is used for a belt conveyor and comprises a flapping sweeper which is arranged above a flapping sweeping area of a conveying belt, can be in contact with the conveying belt and is used for applying periodic flapping to the surface of the conveying belt so as to remove attached materials; the speed reducing motor comprises a motor and a speed reducer and is used for driving the flapping sweeper; the laser vibration measurement sensor is mounted above the conveying belt and is used for measuring vibration parameters of a flapping and sweeping area of the conveying belt in a non-contact manner; the frequency conversion control cabinet is electrically connected with the motor and the laser vibration measurement sensor and used for receiving the vibration parameters collected by the laser vibration measurement sensor and adjusting the working frequency of the motor so that resonance can be generated between the beating sweeper and the beating sweeping area of the conveying belt. The variable frequency motor is adopted as a driving source, local resonance is generated by exciting a specific section of the conveying belt through frequency control, and therefore the efficient cleaning effect is achieved under the condition of low energy consumption.

Description

Technical Field

[0001] This invention relates to the field of belt conveyor technology; specifically, it relates to an adaptive variable frequency beat-and-sweep cleaning system and its control method. Background Technology

[0002] Corrugated sidewall belt conveyors, with their box-like structure formed by corrugated sidewalls and cross diaphragms, can transport bulk materials at steep angles or even vertically. They are widely used in industries such as coal, metallurgy, building materials, and chemicals, significantly reducing equipment footprint and investment costs. However, the special structure of this type of conveyor makes it easy for materials to remain and adhere to the inner side of the conveyor belt sidewalls, the gaps between the cross diaphragms, and the return section. If not cleaned in time, this can lead to problems such as conveyor belt misalignment, drum wear, increased energy consumption, reduced equipment stability, and shortened service life. Therefore, corrugated sidewall belt conveyors are usually equipped with dedicated cleaning devices.

[0003] Existing cleaning technologies are mainly divided into two categories: non-beating and beating. Non-beating cleaning devices include scraper cleaners and brush cleaners. Scraper cleaners remove materials through rigid contact, but they are difficult to adapt to the corrugated structure of the conveyor belt, easily scratching the belt and resulting in incomplete cleaning. Brush cleaners wear out quickly, are ineffective at cleaning highly adhesive materials, and are cumbersome to maintain and replace, increasing downtime costs. Rotary beating cleaners, driven directly by a motor or through a reducer, typically have a relatively fixed operating frequency. In most cases, the excitation frequency of the beating cleaner will not resonate with the overall bending mode of the conveyor belt, resulting in unsatisfactory cleaning performance when dealing with wet and sticky materials, and high energy consumption. Summary of the Invention

[0004] In view of this, the present invention provides an adaptive variable frequency tapping cleaning system and its control method, thereby solving or at least alleviating one or more of the above-mentioned problems and other problems existing in the prior art.

[0005] To achieve the aforementioned objectives, a first aspect of the present invention provides an adaptive variable frequency beat-and-swipe cleaning system for a belt conveyor, the system comprising:

[0006] A beater cleaner is positioned above the beater cleaning area of ​​the conveyor belt and can contact the conveyor belt. It is used to periodically beat the surface of the conveyor belt to remove attached materials.

[0007] A geared motor, including a motor and a reducer, is used to drive the beater sweeper;

[0008] A laser vibration sensor is installed above the conveyor belt to measure the vibration parameters of the conveyor belt's tapping and cleaning area in a non-contact manner.

[0009] The frequency converter control cabinet is electrically connected to the geared motor and the laser vibration sensor. It is used to receive the vibration parameters collected by the laser vibration sensor and adjust the working frequency of the motor so that the beater sweeper resonates with the beater sweeping area of ​​the conveyor belt.

[0010] In the system described above, optionally, the beater sweeper includes a beater wheel and a plurality of buffer rollers, the plurality of buffer rollers being circumferentially evenly distributed on the beater wheel;

[0011] The system also includes a sweeper mounting bracket, which has slots and an adjustment seat. The beater sweeper is mounted on the sweeper mounting bracket via the adjustment seat. The adjustment seat uses an upper and lower opposing set screw structure to adjust the contact distance between the beater wheel and the conveyor belt.

[0012] The geared motor includes a three-phase AC asynchronous frequency converter and a helical gear-worm gear reducer connected thereto, and the reducer adopts a hollow shaft form.

[0013] In the system described above, optionally, the laser vibration sensor is used to achieve multi-point continuous measurement of a specific area of ​​the conveyor belt through an optical scanning mechanism to generate a vibration distribution cloud map;

[0014] The system also includes a vibration sensor mounting bracket, which is separately disposed from the conveyor and the beater cleaner, and the laser vibration sensor is mounted on the vibration sensor mounting bracket.

[0015] The system also includes two irregularly shaped idlers that support the conveyor belt tapping and cleaning area to limit resonance to occur only within the conveyor belt tapping and cleaning area.

[0016] In the system described above, optionally, the frequency converter control cabinet is connected to the centralized control system of the conveyor to realize the synchronous start and stop of the beater and the conveyor.

[0017] The system also includes an audible and visual alarm, which is electrically connected to the frequency converter control cabinet and is used to issue an alarm when the laser vibration sensor malfunctions or the vibration parameters exceed the limits.

[0018] To achieve the aforementioned objective, a second aspect of the present invention provides a control method for a system as described in any of the first aspects, comprising:

[0019] During the system startup phase, the frequency is swept within a preset frequency range, and the vibration parameters of the conveyor belt beat-and-sweep area are collected by the laser vibration sensor to determine the initial resonance reference frequency and the corresponding optimal vibration amplitude.

[0020] During system operation, the vibration parameters of the conveyor belt's tapping and cleaning area are collected in real time, and the deviations of the vibration parameters from the optimal vibration amplitude and the resonant reference frequency are calculated.

[0021] The operating frequency of the motor is dynamically adjusted according to the deviation so that the beater and the beater cleaning area of ​​the conveyor belt maintain a resonant state.

[0022] When the vibration parameters exceed a preset threshold, a protection mechanism is triggered.

[0023] In the control method described above, optionally, the step of sweeping the frequency within a preset frequency range during the system startup phase, collecting vibration parameters of the conveyor belt's tapping and cleaning area through the laser vibration sensor, and determining the initial resonant reference frequency and the corresponding optimal vibration amplitude, specifically includes:

[0024] The motor is started according to the preset value of the natural frequency of the conveyor belt;

[0025] Within a preset range, the frequency is swept according to a preset step size, and each frequency level is operated stably for a certain period of time.

[0026] Record the vibration frequency-vibration amplitude curve, extract the vibration frequency at the maximum vibration amplitude as the resonance reference frequency, the corresponding vibration amplitude as the optimal vibration amplitude, and record the motor no-load current as the overload judgment benchmark.

[0027] In the control method described above, optionally, the step of collecting vibration parameters of the conveyor belt's tapping and cleaning area in real time during system operation, and calculating the deviation of the vibration parameters from the optimal vibration amplitude and the resonant reference frequency, specifically includes:

[0028] The vibration amplitude and frequency are collected by the laser vibration sensor, noise is removed by low-pass filtering, and the average value and fluctuation variance of the filtered signal are calculated.

[0029] The step of dynamically adjusting the operating frequency of the motor according to the deviation, so that the tapping sweeper and the tapping sweeping area of ​​the conveyor belt maintain a resonant state, specifically includes:

[0030] The target range is set based on the optimal vibration amplitude. The motor frequency adjustment strategy is implemented in three working conditions: resonance stability, resonance offset, and sudden change of working condition, based on the deviation between the real-time vibration frequency and the resonance reference frequency.

[0031] The criteria for determining the resonance stability scenario are that the average real-time vibration amplitude is within the target range and the real-time vibration frequency does not deviate from the resonance reference frequency; the adjustment strategy for the resonance stability scenario includes maintaining the current motor frequency and periodically collecting data for verification.

[0032] The condition for determining the resonance offset scenario is that the average real-time vibration amplitude is lower than the lower limit of the target range. The adjustment strategy for the resonance offset scenario is to fine-tune the frequency by a first step length, including: if the real-time vibration frequency is lower than the resonance reference frequency, then the motor frequency is increased by the first step length until the average real-time vibration amplitude returns to the target range; if the real-time vibration frequency is higher than the resonance reference frequency, then the motor frequency is decreased by the first step length; if the average real-time vibration amplitude still does not return to the target range after the frequency adjustment reaches a threshold, then a local frequency sweep is performed to update the resonance reference frequency.

[0033] The judgment condition for the sudden change in operating conditions is that the average real-time vibration amplitude exceeds the upper limit of the target range or the fluctuation variance of the real-time vibration amplitude exceeds the threshold. The adjustment strategy for the sudden change in operating conditions includes starting rapid adjustment, adjusting the frequency according to the second step size, and reducing the motor output torque. The second step size is greater than the first step size. After the average real-time vibration amplitude returns to the target range, the torque is gradually adjusted back to the rated value.

[0034] In the control method described above, optionally, the protection mechanism includes:

[0035] Vibration over-limit protection: when the average real-time vibration amplitude exceeds its preset limit, the motor frequency is reduced and an audible and visual alarm is triggered. If the vibration does not recover within a preset time, the motor is stopped and the fault code is recorded.

[0036] Motor overload protection: When the motor current exceeds its preset limit, reduce the motor frequency and torque until the current returns to the rated range.

[0037] Sensor fault protection: When the laser vibration sensor has no signal output or abnormal data fluctuations, it switches to the preset conveyor belt fixed frequency mode and issues an alarm.

[0038] In the control method described above, optionally, in order to make the conveyor belt resonate with the beater sweeper, the frequency of the motor is... Beating sweeper frequency With conveyor belt frequency The relationship satisfies:

[0039]

[0040] In the formula, p is the number of pole pairs of the motor, i is the reduction ratio of the reducer, s is the slip rate, r is the number of buffer rollers of the beater sweeper, and n is a positive integer;

[0041] The natural frequency of the conveyor belt is Where L is the distance between conveyor rollers, T is the tension of the conveyor belt, and μ is the mass per unit length of the conveyor belt.

[0042] Optionally, in the control method described above, the control method further includes:

[0043] Record the correlation data between resonant frequency, vibration amplitude and cleaning effect under different load periods to form a working condition database;

[0044] The reference calibration is performed automatically and periodically, and the frequency is rescanned during the no-load period of the conveyor to update the resonant reference frequency;

[0045] The running data is uploaded to the host computer via RS485 or Ethernet communication to enable remote debugging.

[0046] The adaptive variable frequency tapping cleaning system of the present invention uses a variable frequency motor as a drive source. By controlling the frequency, it excites a specific section of the conveyor belt to generate local resonance, thereby achieving a high-efficiency cleaning effect under low energy consumption conditions.

[0047] The present invention further provides a control method for the above-described system, which also has the aforementioned advantages. Attached Figure Description

[0048] The disclosure of this invention will become more apparent from the accompanying drawings. It should be understood that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings:

[0049] Figure 1 This is a schematic diagram of the structure of an embodiment of the adaptive variable frequency tapping cleaning system of the present invention;

[0050] Figure 2 This is a schematic diagram of the structure of one side adjustment seat in one embodiment of the adaptive frequency conversion tapping cleaning system of the present invention;

[0051] Figure 3 This is a schematic diagram of the structure of the adjustment seat on the other side in one embodiment of the adaptive frequency conversion tapping cleaning system of the present invention;

[0052] Figure 4 This is a flowchart illustrating an embodiment of the control method for the adaptive variable frequency tapping cleaning system of the present invention.

[0053] Attached reference numerals: 1- Gear motor; 2- Sweeper mounting bracket; 3- Adjusting seat; 4- Beating wheel; 5- Buffer roller; 6- Laser vibration sensor; 7- Vibration sensor mounting bracket; 8- Irregularly shaped roller; 9- Frequency converter control cabinet; 10- Audible and visual alarm. Detailed Implementation

[0054] Referring to the accompanying drawings and specific embodiments, the structure, composition, features, and advantages of the adaptive frequency conversion tapping cleaning system and its control method of the present invention will be described below by way of example. However, all descriptions should not be construed as limiting the present invention in any way.

[0055] Furthermore, for any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the various figures, the present invention still allows for any combination or deletion of these technical features (or their equivalents) without any technical obstacle, and thus these further embodiments according to the present invention should also be considered within the scope of this description.

[0056] It should also be noted that the terms "left", "right", "up", "down", 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 disclosure and simplifying the description, and do not 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 disclosure.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0058] It should also be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0059] Figure 1 This is a schematic diagram of an embodiment of the adaptive frequency conversion tapping cleaning system of the present invention.

[0060] like Figure 1 As shown, in this embodiment, the system includes a geared motor 1, a sweeper mounting bracket 2, an adjusting seat 3, a beater wheel 4, a buffer roller 5, a laser vibration sensor 6, a vibration sensor mounting bracket 7, a shaped roller 8, a frequency converter control cabinet 9, and an audible and visual alarm 10.

[0061] The geared motor 1 includes a motor and a gear reducer connected thereto. The gear reducer can be in the form of a hollow shaft to facilitate system integration and space adaptation. For example, the geared motor 1 adopts a helical gear-worm gear reducer. This type of geared motor 1 has a wide transmission ratio range and can meet the design requirements of the relevant working conditions in this embodiment.

[0062] like Figure 1 As shown, the beater sweeper includes a beater wheel 4 and multiple buffer rollers 5. The beater wheel 4 is driven to rotate by a geared motor 1, thereby applying a beater action of a certain frequency to the conveyor belt through the buffer rollers 5 to shake off the adhering materials. Multiple buffer rollers 5 are evenly distributed around the beater wheel 4 to ensure uniform transmission of the beating force within the contact area. For example, there are 6 buffer rollers 5 arranged in a regular hexagonal pattern.

[0063] like Figure 1 As shown, the sweeper mounting frame 2 spans above the area of ​​the conveyor belt to be swept and cleaned. It has slots on both sides and is equipped with adjustment seats 3. The sweeper and the reduction motor 1 are mounted on the sweeper mounting frame 2 through the adjustment seats 3 on both sides of the sweeper mounting frame 2, so that the sweeper is located above the conveyor belt and the buffer roller 5 can contact the conveyor belt, so that the upper surface of the conveyor belt can be swept during rotation.

[0064] Figure 2 and Figure 3 They are respectively Figure 1 Details of the adjustment seats 3 on both sides of the middle sweeper mounting bracket 2. Figure 2 and Figure 3 As shown, both sides of the adjustment seat 3 adopt an upper and lower opposing top screw structure, which can realize fine adjustment of the contact distance between the beater wheel 4 and the conveyor belt, thereby realizing stepless precise control of the beating force.

[0065] like Figure 1 As shown, the non-contact laser vibration sensor 6 is located above and facing the conveyor belt. It is mounted on a separate vibration sensor mounting bracket 7 to isolate it from other vibration interference. The vibration sensor mounting bracket 7 is separated from the conveyor body and the cleaner mounting bracket 2 to avoid interference from other vibration impacts on the measurement results. This laser vibration sensor 6 can perform multi-point continuous measurement on a specific area of ​​the conveyor belt through its built-in optical scanning mechanism, generating a vibration distribution cloud map of the conveyor belt surface, thereby accurately extracting the real-time vibration frequency of the conveyor belt in that area.

[0066] The variable frequency control cabinet 9, including a controller (e.g., PLC) and a frequency converter, is the core of the system control. It receives the conveyor belt vibration signal fed back by the laser vibration sensor 6 and dynamically adjusts the operating frequency of the sweeper drive motor (the motor in the geared motor 1) to cause the beater sweeper to resonate with the conveyor belt in the cleaning area, thereby exciting and maintaining the resonance state of the conveyor belt cleaning section. In an optional embodiment, the variable frequency control cabinet 9 is also networked with the conveyor centralized control system, enabling the beater sweeper and the conveyor to start and stop synchronously.

[0067] like Figure 1 As shown, the two irregularly shaped idlers 8 together form the support structure of the slapping cleaning zone, limiting the resonance effect to this specific range and effectively suppressing the transmission of vibration energy to the frame and other components. Compared with conventional idlers, the structure of the two irregularly shaped idlers 8 allows for the use of larger bearings, increasing impact resistance.

[0068] The audible and visual alarm 10 triggers a warning signal in abnormal conditions such as sensor 6 malfunction or vibration amplitude exceeding the limit, adding a warning function to the system and enabling unattended operation.

[0069] The basic principle of this system is based on the resonance phenomenon in structural dynamics. Within adjacent idler sections, the conveyor belt can be simplified as a pre-tensioned membrane or thin plate structure, whose local natural frequency is significantly higher than the overall modal frequency of the conveyor system. When the excitation frequency of the cleaning device precisely matches this local natural frequency, the corresponding belt segment will resonate, and the vibration amplitude will increase sharply, thereby applying strong alternating shear and inertial impact to the material adhering to the belt surface, causing it to detach.

[0070] Based on the above mechanism, this embodiment uses a variable frequency motor as the drive source. Through high-precision frequency control, it excites local resonance in a specific section of the conveyor belt, thereby achieving a high-efficiency and thorough cleaning effect under low energy consumption conditions.

[0071] Specifically, the frequency setting and adjustment in this embodiment are based on the following principles and calculations.

[0072] For example, this embodiment can use a commonly used three-phase AC asynchronous variable frequency motor as the sweeper drive motor, and its speed and frequency have the relationship as shown in equation (1):

[0073]

[0074] in The motor's actual rotational speed is expressed in revolutions per minute (r / min); f represents the power supply frequency in Hertz (Hz); s is the slip, determined by the load, typically between 0.01 and 0.05; and p is the number of pole pairs of the motor.

[0075] If the reduction ratio of geared motor 1 is represented by i, then the rotational speed of the beater sweeper is:

[0076]

[0077] The sweeper has multiple small rollers (buffer rollers 5) evenly arranged around the 4-dimensional axis of the beater wheel. The number of small rollers is denoted by r. Therefore, the sweeper beats the conveyor belt r times per revolution. For example, if r=6, the 6 small rollers are arranged in a regular hexagon, beating the conveyor belt 6 times per revolution. The sweeper beats the conveyor belt 6 times per minute.

[0078]

[0079] The frequency relationship between the sweeper and the motor can be expressed by equation (4), taking r=6 as an example.

[0080]

[0081] A commonly used 6-pole motor has a p=3 gear ratio. A geared motor typically has a wide gear ratio range. If a reduction ratio i=40 is selected, substituting r=6, p=3, and i=40, the final frequency of the sweeper is:

[0082]

[0083] The theoretical natural frequency of the lateral vibration of the conveyor belt is calculated as follows (6).

[0084]

[0085] in, L is the natural frequency of the conveyor belt (Hz); L is the distance between the conveyor idlers (m), and in this embodiment, the distance between the two irregularly shaped idlers 8 is 8m; T is the tension of the conveyor belt (N). The mass per unit length of the conveyor belt (kg / m).

[0086] For example, an ST2500 corrugated sidewall conveyor belt is selected. If the idler spacing is 8m and the conveyor belt tension is... N, mass per unit length 110 kg / m, then substituting into the equation, we get...

[0087] That is, the basic reference frequency is approximately 2.094 Hz.

[0088] To achieve resonance between the conveyor belt and the beater cleaner, there should be n is a positive integer, and the motor frequency regulation can be expressed as equation (7). For example, we can substitute r=6, p=3, and i=40.

[0089]

[0090] For example, based on the power supply and motor operating frequency, if the frequency fluctuation range n=1 and the slip s=0.98, then the motor operating frequency should be set to 42.73Hz.

[0091] Based on the above mechanism, the embodiments of the present invention use a variable frequency motor drive, which causes the sweeper to resonate locally with a very short section of the belt surface. This allows for more efficient and thorough cleaning with less energy input, which has important engineering practical significance for the cleaning of conveyor belts and the stable operation of conveyors.

[0092] Figure 4 This is a flowchart illustrating an embodiment of the control method for the adaptive variable frequency tapping cleaning system of the present invention.

[0093] like Figure 4 As shown, this embodiment implements closed-loop control for the system. This embodiment constructs an integrated solution of "vibration sensor + PLC closed-loop adjustment + adaptive resonance tracking," using the conveyor belt vibration signal collected by vibration sensor 6 as the core feedback source. Through closed-loop adjustment, the following objectives are achieved: dynamically tracking the natural frequency of the conveyor belt to maintain optimal resonance, thereby maximizing material drop efficiency; and real-time avoidance of excessive vibration or resonance deviation to protect the conveyor belt, motor, and beater mechanism, balancing cleaning effectiveness and equipment lifespan.

[0094] Specifically, this embodiment adopts a closed-loop control logic architecture including "signal acquisition → status judgment → parameter adjustment → protection feedback", and the specific steps are as follows.

[0095] Step 1: Equipment Startup Phase. After the controller is powered on, it performs a self-test, checking the communication status of sensor 6. If an abnormality is detected, the audible and visual alarm 10 is triggered. The controller controls the frequency converter to start according to the preset value of the calculated natural frequency of the conveyor belt; then, it gradually sweeps the frequency within the preset range, with each frequency level running stably for a certain period of time. For example, the preset range is 35-45Hz, with a step size of 0.5Hz, and each frequency level runs stably for 2 seconds. Vibration sensor 6 collects vibration amplitude in real time, and the controller records the "frequency-amplitude" curve, extracting the frequency at which the amplitude is at its maximum as the initial resonance reference frequency. The corresponding amplitude is taken as the optimal vibration amplitude. Simultaneously record the motor's no-load current This serves as the criterion for overload judgment.

[0096] Step 2: Real-time signal acquisition and processing. Vibration sensor 6 acquires the vibration amplitude A and real-time frequency f. The signal conditioning module performs low-pass filtering to remove noise such as material impact and electromagnetic interference. For example, the cutoff frequency is set to 100Hz. The controller averages the filtered signal. and volatility variance 2 If the variance of the fluctuation exceeds a threshold (e.g., the threshold is set to...), If the condition is determined to be a sudden change (such as a sudden increase in material adhesion), the rapid adjustment mode is triggered.

[0097] Step 3: Resonance state assessment and parameter adjustment. The controller adjusts to the optimal vibration amplitude. Set a target range for the baseline, for example, using " "The target range is defined by combining the real-time frequency f with the reference frequency." To address deviations, the motor frequency is dynamically adjusted, and the process is implemented in three scenarios: resonance stability, resonance offset, and sudden change in operating conditions.

[0098] Resonance stability: when Within the target range and If the current condition is determined to be a normal operating condition with stable resonance, the current motor frequency is maintained, and data is collected once every 10 seconds for verification to avoid drift.

[0099] Resonance offset: when If the current speed is below the lower limit of the target range, it can be determined that the current state has not reached resonance, and this is classified as a resonance offset working condition. This indicates that the cleaning efficiency decreases at this time. In this scenario, the motor frequency is fine-tuned in a certain step size, which can be 0.5-1Hz. Specifically, if... Then gradually increase the frequency until Regression target range; if Then gradually reduce the frequency until Return to the target range; if the frequency adjustment still fails to meet the target after reaching the threshold (e.g., 5Hz), then... If the frequency does not return to the target range, a local frequency sweep will be performed again to update the resonance benchmark. For example, the frequency sweep range can be set to ±10Hz.

[0100] Sudden change in operating conditions: when The variance is higher than the upper limit of the target range or the variance exceeds its preset threshold (e.g. If the current operating condition is determined to be a sudden change (including changes in material / tension), then rapid adjustment is initiated, adjusting the frequency in large steps (e.g., 2Hz) while simultaneously reducing the motor output torque, for example, by 10%-20%. After stabilization, gradually reduce the torque back to the rated value.

[0101] For example, a specific implementation method used in this embodiment is shown in Table 1.

[0102]

[0103] Step 4: Multiple protection mechanisms, including:

[0104] Vibration over-limit protection: If Exceeding the limit (e.g., 1.5) This indicates excessive resonance. The controller immediately lowers the frequency (e.g., by 10Hz) and triggers an audible and visual alarm. If the problem does not resolve within a certain time (e.g., 3 seconds), the system stops and the fault code is recorded.

[0105] Motor overload protection: If the motor current exceeds the limit (e.g., 1.2 times the rated current), the frequency and torque will be reduced simultaneously, for example, by reducing the frequency by 5Hz and the torque by 15%, until the current returns to the rated range;

[0106] Sensor fault protection: If sensor 6 has no signal output or abnormal data fluctuation, the controller switches to "preset conveyor belt fixed frequency mode" and simultaneously issues an alarm for maintenance. In this mode, the preset fixed frequency value of the conveyor belt is used instead of the real-time frequency of the conveyor belt calculated by vibration sensor 6. For example, the judgment condition for abnormal fluctuation can be... >0.5 .

[0107] Step 5: Adaptive iteration based on operating conditions, including:

[0108] The controller has a built-in data storage module that records the correlation data of "resonance frequency - vibration amplitude - cleaning effect" at different times of the day (no load / full load), forming an operating condition database;

[0109] The reference calibration is performed automatically once a week (e.g., weekly). During the idle period of the conveyor, the frequency is rescanned and the resonance reference is updated to adapt to the inherent frequency shift caused by conveyor belt aging and idler wear.

[0110] It supports remote debugging and can upload operating data to the host computer via optional methods such as RS485 or Ethernet communication. It allows manual correction of parameters such as optimal vibration amplitude and adjustment of step size to adapt to special material working conditions.

[0111] Some embodiments of the present invention can at least solve or alleviate one or more of the following technical problems:

[0112] (1) Traditional tapping devices are mostly designed with a fixed frequency and are often driven by pulleys. A single tapping frequency is achieved by fixing the transmission ratio of the pulleys. It is impossible to adjust the parameters for materials with different viscosities and particle sizes, and it is difficult to meet the needs of different operating conditions. The residual materials on the inner side of the sidewall and the gap between the crossbars are not thoroughly cleaned. For example, when conveying high-humidity coal slime or shield tunnel slag, the fixed-frequency low-frequency tapping is not enough to shake off the adhering materials, while when processing dry coal powder, high-frequency tapping will cause excessive dust. Or when the conveyor is fully loaded, the tapping force is insufficient, resulting in a significant decrease in cleaning efficiency. When lightly loaded or unloaded, continuous high-frequency tapping will cause energy waste.

[0113] (2) Traditional beaters are difficult to meet the needs of different operating stages. For example, during the start-up stage of the conveyor belt, the strong beats at a fixed frequency can easily cause material to splash; while during the return run without load, continuous high-frequency beats will cause energy waste.

[0114] (3) Traditional beaters are designed according to the belt width. However, the mechanical properties of conveyor belts with the same belt width are not the same due to the choice of belt strength and the change of tension. This also leads to the same model of beater cleaner having different cleaning effects on conveyors with different belt strengths. If a cleaner is designed separately for each conveyor belt, it will inevitably increase the design cost. Moreover, once the product is produced and delivered, it will be impossible to adjust if the effect is not good after use.

[0115] (4) Ordinary rigid slapping structures are prone to damaging the rubber material of the conveyor belt, shortening its service life. The slapping vibration will also be transmitted to the main frame. If the slapping frequency is not properly controlled, it will cause the frame to resonate, which will cause serious damage to the equipment or even collapse.

[0116] (5) Fixed-frequency driven sweepers are often mistakenly considered to be easy to maintain due to their simple structure, but their actual operation and maintenance costs are high. Traditional fixed-frequency driven beaters often enhance the beating and sweeping effect by increasing the beating force, but the increase in beating force will undoubtedly aggravate the wear of the small rollers on the beater wheel, and the worn small rollers on the beater wheel need to be replaced regularly, increasing the maintenance burden.

[0117] Some embodiments of the present invention can achieve at least one or more of the following beneficial effects:

[0118] (1) Intelligent frequency conversion technology automatically adjusts the tapping frequency (e.g., switching from 50Hz to 20Hz) and intensity based on the frequency of the conveyor belt and material collected and fed back by the non-contact laser vibration sensor. Within a small range, the conveyor belt (including the adhering material) and the tapping cleaner resonate. The resonance is used to increase the amplitude and ensure the best cleaning effect under different working conditions / different operating stages.

[0119] (2) The variable frequency drive can adapt the same cleaner to different belt strength conveyors through electrical control on the basis of the original classification of cleaner models by bandwidth. While ensuring the cleaning effect, it greatly reduces the investment in research and development design. It removes residual materials in the gaps without damaging the conveyor belt, and solves the problem of cleaning dead angles caused by the single force of the fixed frequency device.

[0120] (3) The concept of increasing the amplitude of the conveyor belt by resonance is used to achieve efficient cleaning of wet and sticky materials. The "resonance tapping" method reduces the tapping force, thereby reducing the damage to the tapping wheel and small roller, shortening the downtime maintenance time, and greatly improving the conveying efficiency.

[0121] (4) Compared with ordinary flat rollers, special irregular rollers are designed and installed at both ends of the cleaning area. The large-sized irregular rollers can effectively block the transmission of slapping vibration.

[0122] In summary, some embodiments of the present invention systematically solve or at least alleviate the problems of poor adaptability, poor cleaning effect, high wear and tear, and complex maintenance of traditional beat-and-sweep devices through technologies such as dynamic adjustment, flexible control, and intelligent operation and maintenance, thereby significantly improving cleaning efficiency and reducing overall operation and maintenance costs.

[0123] The technical scope of this invention is not limited to the contents of the above specification. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the scope of this invention.

Claims

1. An adaptive variable frequency tapping cleaning system for belt conveyors, characterized in that, The system includes: A beater cleaner is positioned above the beater cleaning area of ​​the conveyor belt and can contact the conveyor belt. It is used to periodically beat the surface of the conveyor belt to remove attached materials. A geared motor (1) includes a motor and a gear reducer, used to drive the beater sweeper; A laser vibration sensor (6) is installed above the conveyor belt for non-contact measurement of vibration parameters in the conveyor belt's tapping and cleaning area. The frequency converter control cabinet (9) is electrically connected to the geared motor (1) and the laser vibration sensor (6) to receive the vibration parameters collected by the laser vibration sensor (6) and adjust the working frequency of the motor so that the beater and the conveyor belt beater and the sweeping area resonate.

2. The system according to claim 1, characterized in that, The beater sweeper includes a beater wheel (4) and multiple buffer rollers (5), which are evenly distributed circumferentially on the beater wheel (4). The system also includes a sweeper mounting bracket (2), which has slots and an adjustment seat (3). The beater sweeper is mounted on the sweeper mounting bracket (2) via the adjustment seat (3). The adjustment seat (3) uses an upper and lower opposing top screw structure to adjust the contact distance between the beater wheel (4) and the conveyor belt. The geared motor (1) includes a three-phase AC asynchronous frequency converter and a helical gear-worm gear reducer connected thereto, wherein the reducer adopts a hollow shaft form.

3. The system according to claim 1, characterized in that, The laser vibration sensor (6) is used to achieve continuous multi-point measurement of a specific area of ​​the conveyor belt through an optical scanning mechanism, and generate a vibration distribution cloud map; The system also includes a vibration sensor mounting bracket (7), which is separately set from the conveyor and the beater cleaner, and the laser vibration sensor (6) is mounted on the vibration sensor mounting bracket (7). The system also includes two irregularly shaped idlers (8) that support the conveyor belt tapping and cleaning area to limit resonance to occur only within the conveyor belt tapping and cleaning area.

4. The system according to claim 1, characterized in that, The frequency converter control cabinet (9) is connected to the centralized control system of the conveyor to realize the synchronous start and stop of the beater and the conveyor; The system also includes an audible and visual alarm (10), which is electrically connected to the frequency converter control cabinet (9) and is used to issue an alarm when the laser vibration sensor (6) malfunctions or the vibration parameters exceed the limits.

5. A control method for the system as described in any one of claims 1-4, characterized in that, include: During the system startup phase, the frequency is swept within the preset frequency range, and the vibration parameters of the conveyor belt slapping and cleaning area are collected by the laser vibration sensor (6) to determine the initial resonance reference frequency and the corresponding optimal vibration amplitude. During system operation, the vibration parameters of the conveyor belt's tapping and cleaning area are collected in real time, and the deviations of the vibration parameters from the optimal vibration amplitude and the resonant reference frequency are calculated. The operating frequency of the motor is dynamically adjusted according to the deviation so that the beater and the beater cleaning area of ​​the conveyor belt maintain a resonant state. When the vibration parameters exceed a preset threshold, a protection mechanism is triggered.

6. The control method according to claim 5, characterized in that, The steps of sweeping the frequency within a preset frequency range during the system startup phase, collecting vibration parameters of the conveyor belt's tapping and cleaning area through the laser vibration sensor (6), and determining the initial resonant reference frequency and the corresponding optimal vibration amplitude, specifically include: The motor is started according to the preset value of the natural frequency of the conveyor belt; Within a preset range, the frequency is swept according to a preset step size, and each frequency level is operated stably for a certain period of time. Record the vibration frequency-vibration amplitude curve, extract the vibration frequency at the maximum vibration amplitude as the resonance reference frequency, the corresponding vibration amplitude as the optimal vibration amplitude, and record the motor no-load current as the overload judgment benchmark.

7. The control method according to claim 5, characterized in that, The step of collecting vibration parameters of the conveyor belt's tapping and cleaning area in real time during system operation, and calculating the deviation of the vibration parameters from the optimal vibration amplitude and the resonant reference frequency, specifically includes: The vibration amplitude and vibration frequency are collected by the laser vibration sensor (6), noise is removed by low-pass filtering, and the average value and fluctuation variance of the filtered signal are calculated. The step of dynamically adjusting the operating frequency of the motor according to the deviation, so that the tapping sweeper and the tapping sweeping area of ​​the conveyor belt maintain a resonant state, specifically includes: The target range is set based on the optimal vibration amplitude. The motor frequency adjustment strategy is implemented in three working conditions: resonance stability, resonance offset, and sudden change of working condition, based on the deviation between the real-time vibration frequency and the resonance reference frequency. The criteria for determining the resonance stability scenario are that the average real-time vibration amplitude is within the target range and the real-time vibration frequency does not deviate from the resonance reference frequency; the adjustment strategy for the resonance stability scenario includes maintaining the current motor frequency and periodically collecting data for verification. The condition for determining the resonance offset scenario is that the average real-time vibration amplitude is lower than the lower limit of the target range. The adjustment strategy for the resonance offset scenario is to fine-tune the frequency by a first step length, including: if the real-time vibration frequency is lower than the resonance reference frequency, then the motor frequency is increased by the first step length until the average real-time vibration amplitude returns to the target range; if the real-time vibration frequency is higher than the resonance reference frequency, then the motor frequency is decreased by the first step length; if the average real-time vibration amplitude still does not return to the target range after the frequency adjustment reaches a threshold, then a local frequency sweep is performed to update the resonance reference frequency. The judgment condition for the sudden change in operating conditions is that the average real-time vibration amplitude exceeds the upper limit of the target range or the fluctuation variance of the real-time vibration amplitude exceeds the threshold. The adjustment strategy for the sudden change in operating conditions includes starting rapid adjustment, adjusting the frequency according to the second step size, and reducing the motor output torque. The second step size is greater than the first step size. After the average real-time vibration amplitude returns to the target range, the torque is gradually adjusted back to the rated value.

8. The control method according to claim 5, characterized in that, The protection mechanism includes: Vibration over-limit protection: when the real-time average vibration amplitude exceeds its preset limit, the motor frequency is reduced and an audible and visual alarm is triggered. If the vibration does not recover within a preset time, the motor is stopped and the fault code is recorded. Motor overload protection: When the motor current exceeds its preset limit, reduce the motor frequency and torque until the current returns to the rated range. Sensor fault protection: When the laser vibration sensor (6) has no signal output or abnormal data fluctuation, it switches to the preset conveyor belt fixed frequency mode and alarms.

9. The control method according to claim 5, characterized in that, To create resonance between the conveyor belt and the beater sweeper, the frequency of the motor is... Beating sweeper frequency With conveyor belt frequency The relationship satisfies: In the formula, p is the number of pole pairs of the motor, i is the reduction ratio of the reducer, s is the slip rate, r is the number of buffer rollers of the beater sweeper, and n is a positive integer; The natural frequency of the conveyor belt is Where L is the distance between conveyor rollers, T is the tension of the conveyor belt, and μ is the mass per unit length of the conveyor belt.

10. The control method according to claim 5, characterized in that, The control method further includes: Record the correlation data between resonant frequency, vibration amplitude and cleaning effect under different load periods to form a working condition database; The reference calibration is performed automatically and periodically, and the frequency is rescanned and updated during the no-load period of the conveyor to update the resonant reference frequency. The running data is uploaded to the host computer via RS485 or Ethernet communication to enable remote debugging.

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