Automatic blowing device for tobacco impurity removal and control method thereof

Abstract

The application discloses an automatic blowing device for tobacco impurity removal and a control method thereof. The automatic blowing device comprises a blowing execution unit, an air control pressure stabilizing distribution unit and a control unit. The blowing execution unit comprises a rodless air cylinder, a mounting seat and a blowing nozzle. The axis of the rodless air cylinder is parallel to the tobacco conveying direction. Both ends of the rodless air cylinder are fixed with in-place sensors. The mounting seat is slidingly connected to the rodless air cylinder. The blowing nozzle is fixed to the mounting seat. The air control pressure stabilizing distribution unit comprises an air filter valve and a two-position electromagnetic valve. The first air port of the two-position electromagnetic valve is communicated with the first driving air port of the rodless air cylinder, and the second air port is communicated with the first driving air port of the rodless air cylinder and the blowing nozzle. The control unit drives the blowing execution unit to automatically and sequentially blow the detection station. The application can realize automatic, regular and non-stop cleaning operation of the impurity detection and removal device.

Description

Technical Field

[0001] This invention relates to the field of tobacco processing equipment technology, and more specifically to an automatic blowing device and its control method for removing impurities from tobacco, used for online automatic cleaning of the glass in the visual inspection area and removal of the background plate, ensuring camera imaging quality and foreign object detection accuracy. Background Technology

[0002] In the tobacco processing and re-drying production line, the impurity removal machine is a key piece of equipment to ensure the purity of tobacco leaves. It relies on spectral analysis and machine vision technology to identify and automatically remove foreign objects such as metals, plastics, and stones from the tobacco leaves.

[0003] The core performance of an impurity detection and rejection device lies in the image clarity of the detection area. This area mainly consists of a glass protective cover in front of the video cabinet and a rejection background plate used to improve image contrast. However, tobacco production sites are characterized by continuous operation, high humidity, and high dust levels. During prolonged operation, tobacco dust and other particles easily and quickly adhere to the aforementioned glass surface and background plate, leading to blurred camera images, reduced light transmittance, and poor background consistency. This directly causes "false rejection" and "missed rejection" of foreign objects, seriously affecting the quality of the final cigarette product and the stability of the production line.

[0004] To address these issues, the current mainstream solution relies on manual, periodic shutdowns for cleaning. Operators need to stop the production line, open the equipment's protective cover, and manually clean the glass and background panels using compressed air guns, brushes, or cloths. This method is time-consuming (approximately 15 minutes) per cleaning cycle, and frequent start-ups and shutdowns on continuous production lines severely reduce the effective operating rate of the equipment and overall production efficiency. Furthermore, the cleaning cycle depends on manual experience, lacks scientific rigor, and is prone to either untimely cleaning (leading to fluctuations in accuracy) or over-cleaning (wasting manpower).

[0005] Manual cleaning not only consumes a lot of time and increases labor maintenance costs, but also poses risks to personal safety, as operators directly contact delicate optical lenses and electrical components during operation, leading to equipment damage or the introduction of new contamination (such as fingerprints) due to accidental contact.

[0006] Therefore, how to provide a device and method for automatically cleaning the glass and background plate of a cleaning machine is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, the present invention provides an automatic blowing and cleaning device for tobacco impurity removal and its control method, which solves the problems of low efficiency, high labor cost and easy damage to equipment caused by manual cleaning in existing impurity detection and removal devices.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] An automatic purging device for tobacco impurity removal is integrated into an impurity detection and rejection device. The impurity detection and rejection device includes a detection cabinet, an air source and a controller fixed inside the detection cabinet, and the automatic purging device includes: The purging execution unit includes a rodless cylinder, a mounting base, and a nozzle; the rodless cylinder is fixed inside the detection cabinet with its axis parallel to the tobacco conveying direction; both ends of the rodless cylinder are fixed with position sensors; the mounting base is slidably connected to the rodless cylinder; the nozzle is fixed to the mounting base with its outlet corresponding to the detection station inside the detection cabinet. A pneumatically controlled pressure regulating and distribution unit includes an air filter valve and a two-position solenoid valve. The air filter valve is fixed at the output end of the air source. The air inlet of the two-position solenoid valve is connected to the air outlet of the air filter valve. The first air port of the two-position solenoid valve is connected to the first drive air port of the rodless cylinder, and the second air port is connected to the first drive air port of the rodless cylinder and the mouthpiece. The control unit is integrated within the controller. Based on preset instructions, the control unit generates a purging command in one or more ways, such as timed periodic triggering, manual triggering, and / or visual clarity linkage triggering. According to the purging command and the feedback signal from the position sensor, the control unit controls the timing of the action of the two-position solenoid valve to drive the purging execution unit to perform automated graded sequential purging of the detection station.

[0010] Preferably, the nozzle is made of stainless steel, and the angle between its air outlet direction and the detection surface of the detection station is 85° to 90°; the moving speed of the rodless cylinder piston is between 50 mm / s and 1000 mm / s; and the working pressure range of the air source is between 0.3 MPa and 0.5 MPa.

[0011] Preferably, it also includes a cable chain; a slider is slidably connected to the rodless cylinder, and the mounting base is fixed on the slider; one end of the cable chain is fixed on the mounting base, and the other end is fixed on the inner wall of the testing cabinet; the cable chain has a built-in air supply hose, one end of the air supply hose is connected to the nozzle, and the other end is connected to the second drive air port of the rodless cylinder.

[0012] Preferably, the control unit includes an I / O expansion module, which is located inside the controller. The input of the I / O expansion module is connected to at least the signal from the position sensor, the manual button trigger signal on the controller, and the visual signal from the detection cabinet, and the output is connected to the control signal of the two-position solenoid valve (8).

[0013] Preferably, the controller has a built-in fault detection module and an alarm module, and the output of the I / O expansion module is connected to fault and alarm signals.

[0014] Preferably, the purging device is provided in multiple sets, and is respectively arranged on the primary video cabinet glass, the primary rejection background plate, the secondary video cabinet glass, and the secondary rejection background plate inside the testing cabinet.

[0015] Preferably, the timing range of the timed periodic triggering mechanism is 0 to 24 hours, the timing accuracy is ≤1s, and the timing starting point is the start time of the production line or the time when the last purging was completed.

[0016] Preferably, the judgment logic of the visual clarity linkage triggering mechanism is as follows: the control unit continuously receives the real-time image grayscale value data output by the vision system in the detection cabinet. When the average grayscale value of multiple consecutively acquired images is higher than the preset threshold, the control unit automatically determines that the amount of dust adhering to the surface of the detection station exceeds the standard and starts the purging process.

[0017] The present invention also provides a control method for an automatic purging device for tobacco impurity removal, comprising the following steps: S1: The nozzle moves to the initial reset end, triggering the initial end position sensor and entering standby mode. The human-machine interface on the touch controller displays the current standby mode and the remaining purge countdown. S2: The controller monitors all input signals in real time. When the timing cycle ends, or when the manual button is pressed, the human-machine interface triggers purging, or the image grayscale value fed back by the vision system is higher than the threshold for multiple consecutive frames, the control unit generates a purging start command. At the same time, it verifies the operating status signal of the main production line. When the main production line is in normal operating condition, the purging process is started. S3: The control unit outputs a control signal to the two-position solenoid valve. The coil of the two-position solenoid valve is energized, and the rodless cylinder is synchronously driven to move the nozzle from the initial end to the end at a constant speed. At the same time, the nozzle sprays out a high-pressure fan-shaped airflow to fully cover the surface of the detection station. When the nozzle slides to the end position, it triggers the position sensor, cuts off the power supply circuit of the two-position solenoid valve, stops the air supply, and the rodless cylinder drives the nozzle to reset, completing the cleaning of the first area. S4: After receiving the positioning signal that the nozzle has returned to the initial end, the control unit delays for 0.5 seconds to start the next round of purging, repeating the action of step S3 to complete the purging operation; Preferred options also include: S5: After all the blowing actions of the preset areas are completed, the control unit automatically resets all internal timing variables and re-enters standby mode. The touch human-machine interface automatically records the start time, end time and blowing duration of this blowing, and generates a traceable operation log. S6: At any point during the entire purging process, if the controller detects an action timeout or signal abnormality, it will interrupt the current action, trigger an audible and visual alarm, display fault information on the human-machine interface, and simultaneously control the nozzle to safely reset. After maintenance personnel troubleshoot the fault and confirm the reset on the human-machine interface, it will re-enter the standby state.

[0018] As can be seen from the above technical solution, compared with the prior art, the present invention discloses an automatic blowing device and its control method for tobacco impurity removal, which has the following beneficial effects: 1. Significantly improved detection accuracy: Through a visual clarity linkage trigger mechanism, cleaning is achieved on demand, always maintaining optical glass transmittance ≥95%, background board dust adhesion rate below 0.5%, foreign object false rejection rate reduced by more than 60%, and material waste of smoke sheet significantly reduced.

[0019] 2. Significantly improved production efficiency: No manual intervention is required throughout the entire process, and the total time for a single full-process purging is ≤45s. The cleaning operation is completed entirely online, and a single machine can reduce downtime by nearly 100 hours per year, increasing the effective operating rate of the production line by more than 2%.

[0020] 3. Low retrofit cost and strong compatibility: It fully reuses the original PLC hardware of the impurity detection and rejection device, and the function can be upgraded by adding only a few expansion modules. There is no need to replace the original main control system. It is fully compatible with the original detection logic of the equipment and is compatible with the entire series of impurity detection and rejection devices.

[0021] Extremely high operational reliability: The industrial-grade control solution has strong anti-interference capabilities, the full-process fault self-diagnosis mechanism can quickly respond to anomalies, the single-valve synchronous air path design greatly reduces leakage points, and the equipment can operate without failure for more than 2 years.

[0022] Significantly reduced operation and maintenance costs: Completely replaces traditional manual cleaning operations, saving hundreds of man-hours of labor input per unit per year, while avoiding equipment damage and personnel safety hazards caused by manual operation, and realizing fully automated unattended maintenance of the inspection area. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the purging execution unit structure provided by the present invention; Figure 2 This is a schematic diagram of the arrangement of the pneumatically controlled pressure stabilizing distribution unit provided by the present invention.

[0025] Among them, 1-rodless cylinder; 2-mounting base; 3-nozzle; 4-drag chain; 5-air supply hose; 6-air source; 7-air filter valve; 8-two-position solenoid valve. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The cleaning of existing impurity detection and removal devices mainly relies on manual periodic shutdowns for cleaning, which consumes a lot of time and increases labor costs. In addition, during operation, operators directly contact the delicate optical lenses and electrical components, which poses a risk of equipment damage or the introduction of new contamination (such as fingerprints) due to accidental contact, and also poses a risk to personal safety. In view of this, this embodiment discloses an automatic blowing device and its control method for tobacco impurity removal, which aims to achieve automatic, periodic, and non-stop cleaning of the impurity detection and removal device.

[0028] See appendix Figure 1 and attached Figure 2According to an embodiment of the present invention, an automatic purging device for tobacco impurity removal is integrated into an impurity detection and rejection device, eliminating the need for additional external installation space. The impurity detection and rejection device includes a detection cabinet, an air source 6 fixed inside the detection cabinet, and a controller. The automatic purging device includes a purging execution unit, an air control and pressure stabilization distribution unit, and a control unit. The purging execution unit includes a rodless cylinder 1, a mounting base 2, and a nozzle 3. The rodless cylinder 1 is fixed inside the detection cabinet with its axis parallel to the tobacco conveying direction. Position sensors are fixed at both ends of the rodless cylinder 1. The mounting base 2 is slidably connected to the rodless cylinder 1. The nozzle 3 is fixed to the mounting base 2, and its air outlet corresponds to the detection station inside the detection cabinet. The air control and pressure stabilization distribution unit includes an air filter valve 7 and a two-position solenoid valve 8. The air filter valve 7 is fixed at the output of the air source 6. The inlet of the two-position solenoid valve 8 is connected to the outlet of the air filter valve 7; the first port of the two-position solenoid valve 8 is connected to the first drive port of the rodless cylinder 1, and the second port is connected to the first drive port of the rodless cylinder 1 and the nozzle 3; when the first port of the two-position solenoid valve 8 is open, the piston of the rodless cylinder can be reset; when the second port is open, the reciprocating motion of the piston in the rodless cylinder 1 and the start and stop of the blowing air supply of the nozzle can be realized simultaneously; the control unit is integrated in the controller. Based on preset instructions, the control unit generates a blowing command in one or more ways, such as timed periodic triggering, manual triggering and / or visual clarity linkage triggering, and controls the action sequence of the two-position solenoid valve 8 according to the blowing command and the feedback signal of the position sensor, so as to drive the blowing execution unit to perform automated graded sequential blowing of the detection station.

[0029] In this embodiment, the control unit includes an I / O expansion module, which is located inside the controller. The input terminal of the I / O expansion module is connected to at least the signal from the position sensor, the manual button trigger signal on the controller, and the visual signal from the detection cabinet. The output terminal is connected to the control signal of the two-position solenoid valve 8.

[0030] To further optimize the above technical solution, the controller has a built-in fault detection module and an alarm module, and the output of the I / O expansion module is connected to fault and alarm signals.

[0031] The judgment rule of the full-process fault self-diagnosis logic is as follows: after the controller issues the start command of the two-position solenoid valve, if no feedback signal is received from the end position sensor within 6 seconds, or if no feedback signal is received from the initial end position sensor within 6 seconds after the two-position solenoid valve issues the reset command, it is judged as a purging fault. After the fault is triggered, the controller immediately cuts off the power supply circuit of the two-position solenoid valve, drives the alarm module to issue an audible and visual prompt, and at the same time pops up the corresponding fault code and fault handling guide on the human-machine interface, automatically locks the subsequent purging action, and does not output any shutdown signal to the main production line, so as not to affect the continuous operation of the tobacco main production line at all.

[0032] The control unit in this embodiment completely reuses the original controller hardware of the impurity detection and removal device, and only expands its functionality by adding a digital I / O expansion module. The controller includes a 7-inch touch screen human-machine interface, an audible and visual alarm component, and a signal isolation barrier. Two slotted photoelectric position sensors are installed at the initial reset end and the end stroke end of the rodless cylinder, respectively, to provide real-time feedback on the position status of the mouthpiece. The signal isolation barrier is connected in series in all external signal lines to filter electromagnetic interference signals generated by frequency converters and motors in the tobacco workshop.

[0033] To further optimize the above technical solution, the purging device is provided in multiple sets, which are respectively arranged on the primary video cabinet glass, the primary rejection background plate, the secondary video cabinet glass, and the secondary rejection background plate inside the testing cabinet.

[0034] To further optimize the above technical solution, the nozzle 3 is made of stainless steel, and the angle between its air outlet direction and the detection surface of the detection station is 85° ~ 90°; the moving speed of the rodless cylinder 1 is 50mm / s to 1000mm / s; and the working pressure range of the air source 6 is 0.3MPa to 0.5MPa.

[0035] The stroke of the rodless cylinder completely covers the full width of the single-channel detection area of ​​the impurity detection and rejection device, with the stroke tolerance controlled within ±2mm. The reciprocating speed of the piston inside the rodless cylinder can be freely adjusted by the controller program parameters, and the position repeatability during the movement is ≤±0.5mm.

[0036] The nozzle outlet is flat, and its width perfectly matches the width of the inspection station to be cleaned. The gap width of the outlet is set to 0.8mm. During purging, a fan-shaped high-pressure airflow with uniform width is formed. The effective purging coverage width of the airflow is ≥120mm. Under a working pressure of 0.4MPa, the airflow velocity at the nozzle outlet can reach 180m / s, which can completely peel off the soot, sticky water vapor and dust clumps attached to the glass surface.

[0037] To further optimize the above technical solution, the air filter valve has a filtration accuracy of 5μm, which can completely intercept liquid water, oil mist and solid impurities in the compressed air in the factory area, prevent impurities from clogging the air outlet gap of the nozzle, and prevent compressed air with oil and water from contaminating the optical glass surface of the detection area.

[0038] To further optimize the above technical solution, the response time of the two-position solenoid valve is ≤8ms. After adopting this single-valve synchronous control scheme, compared with the traditional dual-valve scheme where the cylinder drive valve and the mouthpiece air supply valve are independently controlled, the total number of air circuit joints is reduced by 32%, the number of air circuit leakage points is reduced simultaneously, and the failure rate of the overall air control system can be reduced by more than 45%.

[0039] To further optimize the above technical solution, the controller's internal control program is written using a structured ladder diagram. The program's scan cycle is ≤50ms, and it integrates five core control logics: signal filtering processing logic: all input signals undergo three consecutive sampling verifications; only when the three consecutive sampling results are completely consistent is the signal considered valid, thoroughly filtering out signal jitter caused by electromagnetic interference at the scene; multi-mode trigger judgment logic: three independent purging trigger mechanisms are built-in: timed periodic triggering, manual triggering, and visual clarity linkage triggering. These three trigger mechanisms are connected in parallel using "OR logic," and purging can be started as long as any one of the trigger conditions is met. Process; Hierarchical sequential purging timing logic: According to the preset area priority, the purging actions of different detection stations are completed sequentially. The purging process of the next area will only start after the purging action of the previous area is completely completed and the piston is successfully reset, so as to avoid mutual interference of purging airflow between different areas; Visual parameter configuration logic: All operating parameters can be modified online through the touch human-machine interface. The modified parameters are automatically stored in the power-off retention register of the controller and will not be lost after the equipment is powered off and restarted; Full-process fault self-diagnosis logic: Real-time monitoring of the operating status of the entire purging process. Once an abnormality such as action timeout or signal loss occurs, safety protection actions are immediately executed.

[0040] To further optimize the above technical solution, a cable chain 4 is also included; a slider is slidably connected to the rodless cylinder 1, and the mounting base 2 is fixed on the slider; one end of the cable chain 4 is fixed to the mounting base 2, and the other end is fixed to the inner wall of the testing cabinet; the cable chain 4 has a built-in air supply hose 5, one end of which is connected to the nozzle 3, and the other end is connected to the second drive air port of the rodless cylinder 1. The cable chain 4 constrains the movement path of the air supply hose 5 throughout the entire process, preventing the air supply hose 5 from getting tangled, bent, worn, or scraping against external structures during reciprocating motion.

[0041] To further optimize the above technical solution, the timing range of the timed periodic triggering mechanism is 0~24 hours, the timing accuracy is ≤1s, the timing start point is the start time of the production line or the time of the last purging completion, and it supports customizing the purging interval according to different seasons and different material dust adhesion speeds.

[0042] To further optimize the above technical solution, the judgment logic of the visual clarity linkage triggering mechanism is as follows: the control unit continuously receives the real-time image grayscale value data output by the vision system in the inspection cabinet. When the average grayscale value of 5 consecutively acquired images is higher than the preset threshold of 220, the control unit automatically determines that the amount of dust adhering to the surface of the inspection station exceeds the standard, and the purging process can be started without manual intervention.

[0043] To further optimize the above technical solution, the preset purging sequence of the hierarchical sequential purging logic is as follows: purging of the glass protective cover of the video cabinet in the first-level detection channel → purging of the background board removal in the first-level detection channel → purging of the glass protective cover of the video cabinet in the second-level detection channel → purging of the background board removal in the second-level detection channel. The purging duration of each area can be set independently, and the purging duration of different areas supports differentiated configuration.

[0044] A control method for an automatic purging device for tobacco impurity removal according to this embodiment includes the following steps: S1: The nozzle 3 moves to the initial reset end, triggering the initial end position sensor and entering the standby state. The human-machine interface on the touch controller displays the current standby state and the remaining purge countdown. S2: The controller monitors all input signals in real time. When the timing cycle ends, or when the manual button is pressed, the human-machine interface triggers purging, or the image grayscale value fed back by the vision system is higher than the threshold for multiple consecutive frames, the control unit generates a purging start command. At the same time, it verifies the operating status signal of the main production line. When the main production line is in normal operating condition, the purging process is started. S3: The control unit outputs a control signal to the two-position solenoid valve 8. The coil of the two-position solenoid valve 8 is energized, and the rodless cylinder 1 is synchronously driven to move the nozzle 3 from the initial end to the end at a constant speed. At the same time, the nozzle 3 sprays out a high-pressure fan-shaped airflow to fully cover the surface of the detection station. When the nozzle 3 slides to the end position, it triggers the positioning sensor, cuts off the power supply circuit of the two-position solenoid valve 8, stops the air supply, and the rodless cylinder 1 drives the nozzle 3 to reset, completing the cleaning of the first area. S4: After receiving the signal that the nozzle 3 has returned to the initial position, the control unit delays for 0.5 seconds to start the next round of blowing and repeats the action of step S3 to complete the blowing operation; S5: After all the blowing actions of the preset areas are completed, the control unit automatically resets all internal timing variables and re-enters standby mode. The touch human-machine interface automatically records the start time, end time and blowing duration of this blowing, and generates a traceable operation log. S6: At any point during the entire purging process, if the controller detects an action timeout or signal abnormality, it will interrupt the current action, trigger an audible and visual alarm, display fault information on the human-machine interface, and simultaneously control the nozzle 3 to safely reset. After maintenance personnel troubleshoot the fault and confirm the reset on the human-machine interface, it will re-enter the standby state.

[0045] The entire purging process takes ≤45 seconds, requires no manual intervention, and does not require stopping the material conveying of the impurity detection and rejection device. The cleaning operation is completed online while the production line is running continuously.

[0046] To further optimize the above technical solution, a purging count statistics function is also integrated. The controller automatically accumulates the total number of historical purgings. When the accumulated number of purgings reaches the preset maintenance threshold, the human-machine interface will automatically pop up a prompt message to remind maintenance personnel to regularly check the wear of the air outlet gap of the nozzle, the aging of the cable chain, and the sealing status of the air circuit.

[0047] Example 1 Taking the actual modification of the FT416 dual-channel impurity detection and rejection device as an example, this modification was completed entirely within the existing equipment frame, without the need for any additional external mounting brackets. First, the rodless cylinder was fixed to the side of the glass protective cover of the primary detection channel using a dedicated mounting plate. The installation position was adjusted to ensure that the air outlet of the duckbill flat nozzle was 15mm from the glass surface, and the included angle was strictly maintained at 90°. Then, the cable chain was fixed along the cylinder's movement trajectory, and a PU air supply hose was threaded through it before connecting it to the output of the filter pressure reducing valve in the pneumatic control cabinet. For the electrical control section, two digital input points were added to the existing Siemens S7-1200 PLC of the FT416 equipment, connecting two position sensors. One digital output point was added, connecting a two-position solenoid valve. All signal lines were connected in series with a signal isolation barrier before being connected to the I / O expansion module to avoid electromagnetic interference from the on-site frequency converter.

[0048] On the 7-inch touchscreen HMI, set the following parameters: timed purging cycle to 30 minutes, visual clarity linkage threshold to image grayscale value of 220, primary glass purging time to 12s, primary background plate purging time to 18s, secondary glass purging time to 12s, secondary background plate purging time to 18s, piston movement speed to 400mm / s, and fault response timeout to 6s.

[0049] After the equipment is put into operation, the system operates automatically according to the set parameters: it automatically starts purging once every 30 minutes. When encountering high dust material conditions, the vision system detects that the image grayscale value exceeds the standard and will automatically trigger purging in advance without manual intervention.

[0050] After six months of continuous operation, statistics show that the device has achieved fully automated cleaning of the detection area without human intervention. The rate of false foreign object rejection has decreased from 1.2% before the modification to 0.4%. The single device reduces manual cleaning and maintenance time by 120 hours per year, and the effective operating rate of the production line has increased by 2.3%, fully achieving the expected invention effect.

[0051] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0052] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An automatic purging device for tobacco impurity removal, integrated into an impurity detection and rejection device, the impurity detection and rejection device comprising a detection cabinet, an air source (6) fixed inside the detection cabinet, and a controller, characterized in that, The automatic purging device includes: The purging execution unit includes a rodless cylinder (1), a mounting base (2), and a nozzle (3); the rodless cylinder (1) is fixed inside the detection cabinet and its axis is parallel to the tobacco conveying direction; both ends of the rodless cylinder (1) are fixed with position sensors; the mounting base (2) is slidably connected to the rodless cylinder (1); the nozzle (3) is fixed on the mounting base (2) and its air outlet corresponds to the detection station inside the detection cabinet; The pneumatic pressure regulating and distribution unit includes an air filter valve (7) and a two-position solenoid valve (8). The air filter valve (7) is fixed at the output end of the air source (6). The air inlet of the two-position solenoid valve (8) is connected to the air outlet of the air filter valve (7). The first air port of the two-position solenoid valve (8) is connected to the first drive air port of the rodless cylinder (1), and the second air port is connected to the first drive air port of the rodless cylinder (1) and the nozzle (3). The control unit is integrated within the controller. Based on a preset instruction, the control unit generates a purging instruction in one or more ways, such as timed periodic triggering, manual triggering, and / or visual clarity linkage triggering. According to the purging instruction and the feedback signal from the position sensor, the control unit controls the action sequence of the two-position solenoid valve (8) to drive the purging execution unit to perform automated graded sequential purging of the detection station.

2. An automatic blowing device for removing impurities from tobacco according to claim 1, characterized in that, The nozzle (3) is made of stainless steel, and the angle between its air outlet direction and the detection surface of the detection station is 85° ~ 90°; the piston of the rodless cylinder (1) moves at a speed of 50mm / s to 1000mm / s; the working pressure range of the air source (6) is 0.3MPa to 0.5MPa.

3. An automatic blowing device for tobacco impurity removal according to claim 1, characterized in that, It also includes a cable chain (4); a slider is slidably connected to the rodless cylinder (1), and the mounting base (2) is fixed on the slider; one end of the cable chain (4) is fixed on the mounting base (2), and the other end is fixed on the inner wall of the testing cabinet; the cable chain (4) has a built-in air supply hose (5), one end of the air supply hose (5) is connected to the nozzle (3), and the other end is connected to the second drive air port of the rodless cylinder (1).

4. An automatic blowing device for tobacco impurity removal according to claim 1, characterized in that, The control unit includes an I / O expansion module, which is located inside the controller. The input of the I / O expansion module is connected to at least the signal from the position sensor, the manual button trigger signal on the controller, and the visual signal from the detection cabinet. The output is connected to the control signal of the two-position solenoid valve (8).

5. An automatic blowing device for tobacco impurity removal according to claim 4, characterized in that, The controller has a built-in fault detection module and an alarm module, and the output of the I / O expansion module is connected to fault and alarm signals.

6. An automatic blowing device for tobacco impurity removal according to claim 5, characterized in that, The purging device is provided in multiple sets, and is respectively arranged on the primary video cabinet glass, the primary rejection background plate, the secondary video cabinet glass, and the secondary rejection background plate inside the testing cabinet.

7. An automatic blowing device for tobacco impurity removal according to claim 1, characterized in that, The timing period triggering mechanism has a timing range of 0 to 24 hours, a timing accuracy of ≤1 second, and the timing start point is the production line start-up time or the time when the last purging was completed.

8. An automatic blowing device for removing impurities from tobacco according to claim 1, characterized in that, The judgment logic of the visual clarity linkage triggering mechanism is as follows: the control unit continuously receives the real-time image grayscale value data output by the vision system in the detection cabinet. When the average grayscale value of multiple consecutively acquired images is higher than the preset threshold, the control unit automatically determines that the amount of dust adhering to the surface of the detection station exceeds the standard and starts the purging process.

9. A control method for an automatic purging device for tobacco impurity removal according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1: The nozzle (3) moves to the initial reset end, triggering the initial end position sensor and entering the standby state. The human-machine interface on the touch controller displays the current standby state and the remaining purge countdown. S2: The controller monitors all input signals in real time. When the timing cycle ends, or when the manual button is pressed, the human-machine interface triggers purging, or the image grayscale value fed back by the vision system is higher than the threshold for multiple consecutive frames, the control unit generates a purging start command. At the same time, it verifies the operating status signal of the main production line. When the main production line is in normal operating condition, the purging process is started. S3: The control unit outputs a control signal to the two-position solenoid valve (8). The coil of the two-position solenoid valve (8) is energized and synchronously drives the rodless cylinder (1) to move the nozzle (3) from the initial end to the end at a constant speed. At the same time, the nozzle (3) sprays out a high-pressure fan-shaped airflow to fully cover the surface of the detection station. When the nozzle (3) slides to the end position, it triggers the position sensor, cuts off the power supply circuit of the two-position solenoid valve (8), stops the air supply, and drives the nozzle (3) to reset, completing the cleaning of the first area. S4: After the control unit receives the signal that the nozzle (3) has returned to the initial end, it delays for 0.5s to start the next round of purging, repeats the action of step S3, and completes the purging operation.

10. The control method of the automatic blowing device for tobacco impurity removal as described in claim 9, characterized in that, Also includes: S5: After all the blowing actions of the preset areas are completed, the control unit automatically resets all internal timing variables and re-enters standby mode. The touch human-machine interface automatically records the start time, end time and blowing duration of this blowing, and generates a traceable operation log. S6: At any point during the entire purging process, if the controller detects an action timeout or signal abnormality, it will interrupt the current action, trigger an audible and visual alarm, display fault information on the human-machine interface, and simultaneously control the nozzle (3) to safely reset. After the maintenance personnel have investigated the fault and confirmed the reset on the human-machine interface, it will re-enter the standby state.

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