Feeding control system of automatic packaging machine

Abstract

The invention relates to a feeding control system of an automatic packaging machine, which comprises a stock bin, a conveyor belt mechanism, a dynamic weighing sensor and a vibrating feeder, the vibrating feeder is connected with the conveyor belt mechanism through a flow guide plate, the stock bin is connected with the conveyor belt mechanism through a flow guide groove, the inclination angle of the flow guide groove is adjusted by a stepping motor, and the conveyor belt mechanism is driven by a servo motor. The dynamic weighing sensor is arranged between the output end of the conveying belt mechanism and a material receiving opening of the vibrating feeder, the amplitude of the vibrating feeder is adjusted through a linear electromagnetic driver, and the upper portion, the middle portion and the lower portion of the stock bin are respectively provided with an ultrasonic level gage. When the material height in the middle of the stock bin is lower than a set threshold value, the stepping motor adjusts the inclination angle of the diversion trench to be increased; the servo motor adjusts the rotating speed when the flow is abnormal; and when the flow fluctuation amplitude exceeds a threshold value, the driving current of the linear electromagnetic driver is adjusted to be 1.2-1.8 times of the current value. The system is mainly used for material supply control of the automatic packaging machine, dynamic coordination of multiple executing mechanisms can be achieved, and the material supply stability and the metering precision are improved.

Description

Technical Field

[0001] The present invention belongs to the field of packaging machines. More specifically, the present invention relates to a feeding control system for an automatic packaging machine. Background Art

[0002] In the feeding control system of automatic packaging machinery, the continuous and stable supply of materials is a key link to achieve efficient production. The prior art generally adopts a combination of a diversion chute with a fixed structure and a mechanical regulating device to achieve material transportation, but there are still multiple technical bottlenecks in actual operation.

[0003] Firstly, the fixed inclination angle design of the diversion chute makes it difficult for the material flow state to adapt to the requirements of different working conditions. When the bulk density of the material in the silo changes or there are differences in the material properties, the diversion chute with a fixed angle is likely to cause problems such as poor material flow or excessive pouring. Especially when dealing with materials prone to arching, the material frequently forms blockages at the outlet of the diversion chute, and manual intervention is required for angle adjustment, which not only reduces production efficiency but also increases the safety risk of operators. Although some systems attempt to use a mechanical angle adjustment mechanism, its adjustment accuracy is low and the response speed is slow, and it cannot achieve dynamic adjustment during the production process.

[0004] Secondly, there is a lack of a precise coordination mechanism between the conveyor belt speed control and the material flow rate. Traditional control systems mostly adopt an open-loop control strategy, and the conveying speed is controlled by a preset speed curve, but the actual flow rate will have significant deviations due to multiple factors such as the stacking form of the material and humidity changes. The prior art attempts to perform compensation control by adding a weighing feedback link, but due to the mismatch between the sensor sampling frequency and the response speed of the actuator, there is an obvious lag in the adjustment process, and it is difficult to effectively suppress the instantaneous flow rate fluctuations.

[0005] The amplitude control of the vibrating feeder is another technical difficulty. Traditional electromagnetic vibrators use relay-type on-off control, and there are obvious step changes in its amplitude adjustment, which is likely to cause secondary fluctuations in material transportation. Especially when dealing with powdery materials with poor fluidity, the sudden change in amplitude will cause intermittent material breakage or gushing at the feeding port. Although some improvement schemes introduce analog quantity adjustment technology, limited by the mechanical inertia of the driving mechanism, the actual amplitude adjustment response time is still as long as 3 - 5 seconds, which cannot meet the high-frequency dynamic adjustment requirements.

[0006] In terms of level monitoring, existing systems mostly adopt a single level detection device, which is difficult to accurately reflect the true distribution state of materials in the silo. Due to the natural stacking angle effect of materials in the silo, the level height difference between the central area and the edge area can reach more than 30%. Such monitoring blind spots are likely to cause local materials to be exhausted in advance, forming voids, or causing bridging due to excessive accumulation at the edge. Although attempts have been made to increase multi-point detection devices, the fusion processing algorithms for data from different detection points are not yet mature, and misjudgment often occurs.

[0007] The root cause of the above technical problems lies in the lack of an effective coordination mechanism among the execution units of the traditional control system. The differences in the response characteristics of each link lead to a decline in the overall dynamic performance of the system. For example, the response time for speed adjustment of the conveyor belt is about 0.5 - 1 second, while the amplitude adjustment of the vibrating feeder requires more than 3 seconds. This mismatch in time constants makes it difficult for the system to establish a stable closed-loop control. In addition, due to the time-varying and non-linear characteristics of material characteristic parameters, the control models based on fixed parameters generally have problems with insufficient adaptability in practical applications. These technical bottlenecks severely restrict the operating speed and metering accuracy of packaging machinery. Especially when dealing with high-value-added materials, a small flow deviation will result in significant economic losses. How to achieve dynamic coordinated control of multiple actuators has become a technical problem that urgently needs to be solved to improve the performance of the feeding system. Summary of the Invention

[0008] An object of the present invention is to solve at least the above problems and provide at least the advantages described hereinafter.

[0009] An object of the present invention is to solve the problems that the inclination angle of the diversion chute in the traditional feeding system is fixed and cannot be dynamically adjusted according to the material height in the silo, resulting in poor material flow stability; there is a lag in the conveyor belt speed control and flow feedback, making it difficult to maintain an accurate flow rate; the response speed of the amplitude adjustment of the vibrating feeder is slow and cannot suppress flow fluctuations in a timely manner; single level detection cannot reflect the true state of material distribution in the silo and is prone to causing local material exhaustion or bridging phenomena.

[0010] An object of the present invention is to solve the problems that the inner wall of the diversion chute lacks a material guiding structure, and high-humidity or viscous materials are easily attached and accumulated, resulting in a reduction in the flow cross-section; traditional humidity detection means cannot monitor the moisture content change of materials in the diversion chute in real time, affecting the adjustment of subsequent process parameters.

[0011] An object of the present invention is to solve the problems that the existing humidity adjustment methods only rely on mechanical actions in a single direction and cannot provide differential treatment for materials with different humidities, resulting in caking of high-humidity materials or dusting of low-humidity materials.

[0012] An object of the present invention is to solve the problem that when the fluidity of materials decreases in a high-humidity environment, the driving force of the vibrating feeder is not synchronously adapted, resulting in insufficient amplitude and uneven feeding.

[0013] One object of the present invention is to solve the problem that the excessive pressure difference between the internal pressure of the diversion groove and the external environment will exacerbate the phenomenon of material sticking to the wall, and the traditional filtering device cannot dynamically balance the pressure and is prone to blockage.

[0014] One object of the present invention is to solve the problem that viscous materials remain on the inner wall of the diversion groove to form a accumulation layer, and the conventional mechanical scraping device is prone to wear and has poor cleaning effect; the drying gas injection and mechanical actions are not coordinated, resulting in low energy consumption efficiency.

[0015] One object of the present invention is to solve the problem that the temperature fluctuation of compressed air affects the physical property stability of materials, low temperature causes condensation, and high temperature accelerates material oxidation; the fixed-angle air jet cannot adapt to the dynamic pressure difference change.

[0016] One object of the present invention is to solve the problem that fine particle materials remain due to electrostatic adsorption on the surface of the metal flipper, and the traditional coating material resistivity mismatch causes charge accumulation.

[0017] One object of the present invention is to solve the problem that the air pump pressure control does not comprehensively consider the correlation between the material resistance characteristics and the pressure difference, resulting in insufficient air pressure regulation accuracy.

[0018] One object of the present invention is to solve the problem that the traditional flow calculation uses the simple difference method, and the sampling noise is prone to cause misjudgment and cannot accurately identify the true fluctuation trend.

[0019] Another object of the present invention is to provide a feeding control system for an automatic packaging machine, which can dynamically adjust the inclination angle of the diversion groove through a stepping motor, adapt to different material accumulation states, and prevent blockage; realize precise flow regulation through the closed-loop control of a servo motor and a dynamic weighing sensor; accurately identify the material distribution in the silo through the cooperation of three ultrasonic level gauges, and avoid local cavities or bridging.

[0020] To achieve these objects and other advantages according to the present invention, a feeding control system for an automatic packaging machine is provided, which includes a silo, a conveyor belt mechanism, a dynamic weighing sensor, and a vibrating feeder. The vibrating feeder is directly below the output end of the conveyor belt mechanism, and the two are connected by a diversion plate. The bottom outlet of the silo is connected to the input end of the conveyor belt mechanism through a diversion trough, and the inclination angle of the diversion trough is adjusted by a stepping motor. The control end of the stepping motor is connected to a central controller. The driving motor of the conveyor belt mechanism is a servo motor, and the speed control end of the servo motor is connected to the central controller. The dynamic weighing sensor is arranged between the output end of the conveyor belt mechanism and the material receiving port of the vibrating feeder, and the signal output end of the dynamic weighing sensor is connected to the central controller. The central controller calculates the instantaneous flow rate of the material based on the weight data continuously collected by the dynamic weighing sensor. The amplitude adjustment mechanism of the vibrating feeder is realized by a linear electromagnetic driver, and the control end of the linear electromagnetic driver is connected to the central controller. Ultrasonic level gauges are respectively arranged in the upper, middle, and lower parts inside the silo, and the signal output ends of the three groups of ultrasonic level gauges are connected to the central controller. When the height of the middle material in the silo is lower than the set threshold, the central controller drives the stepping motor to adjust the inclination angle of the diversion trough to increase by 5 - 15 degrees. When the flow rate is lower than the set lower limit, the central controller controls the servo motor to increase the speed of the servo motor at a rate of 0.5 - 2% per second. When the flow rate is higher than the set upper limit, the central controller controls the servo motor to decrease the speed of the servo motor at a rate of 0.5 - 2% per second. The central controller adjusts the linear electromagnetic driver according to the flow rate fluctuation amplitude in three consecutive sampling periods of the dynamic weighing sensor. When the fluctuation amplitude exceeds the threshold, the driving current of the linear electromagnetic driver is adjusted to 1.2 - 1.8 times the current value.

[0021] Preferably, three groups of rotating vane groups are arranged on the inner wall of the diversion trough of the present invention along the material flow direction. Each group of rotating vane groups includes two parallel metal shafts, and 6 sector-shaped vanes are installed at intervals on the metal shafts. The included angle between adjacent vanes is 60 degrees. The driving mechanism of the rotating vane group includes a micro reduction motor, and the micro reduction motor is connected to the metal shaft through a coupling, and the rotation directions of adjacent two groups of rotating vane groups are opposite. A microwave humidity sensor is installed outside the diversion trough, and the probe of the microwave humidity sensor extends into the diversion trough and keeps a gap of 3 - 5 mm from the material contact surface.

[0022] Preferably, the signal output end of the microwave humidity sensor of the present invention is connected to the central controller, and the central controller adjusts the rotation frequency of the micro reduction motor according to the detected material humidity value: when the material humidity exceeds 18%, the central controller adjusts the micro reduction motor to drive the rotating vane group to rotate forward and backward alternately at a frequency of 20 - 40 Hz. When the material humidity is lower than 12%, the central controller adjusts the micro reduction motor to rotate unidirectionally at a frequency of 5 - 15 Hz.

[0023] Preferably, when the micro reduction motor of the present invention operates at a frequency higher than 30 Hz, the drive current of the linear electromagnetic driver synchronously increases to 1.1 - 1.3 times the reference value.

[0024] Preferably, an air pressure balance channel is provided at the bottom of the diversion channel of the present invention. The air pressure balance channel communicates the inside of the diversion channel with the external environment. A detachable filter screen is installed in the channel. The mesh diameter of the filter screen is 0.5 - 0.8 mm. A differential pressure sensor is provided at the outlet end of the air pressure balance channel. The detection ends of the differential pressure sensor are respectively connected to the inside and the external environment of the diversion channel. When the pressure difference inside and outside the diversion channel exceeds 50 Pa, the central controller adjusts the rotation frequency of the micro reduction motor to increase by 10 - 20 Hz and lasts for 5 - 10 seconds.

[0025] Preferably, an axial air flow channel is provided inside the metal shaft of the present invention. The air flow channel is connected to an air pump through a rotary joint. The air pump outputs dry compressed air with a pressure of 0.2 - 0.5 MPa. Two rows of air jet holes are symmetrically arranged on both sides of the inner wall of the diversion channel. The distance between the air jet holes is 15 - 25 mm. The air jet holes are communicated with the air flow channel of the metal shaft through air ducts. The jet direction of the air jet holes forms an angle of 30 - 45 degrees with the inner wall of the diversion channel, and the jet direction points to the gap between the adjacent rotary vane groups. The rotation speed of the metal shaft is synchronously matched with the air pump jet frequency. When the micro reduction motor operates at a frequency higher than 30 Hz, the central controller controls the air pump jet frequency to be adjusted to 1 / 3 - 1 / 2 of the rotation speed. When the detection value of the microwave humidity sensor is lower than 12% and lasts for 5 - 10 seconds, the central controller controls the air pump to work at a pulse interval of 0.3 seconds, and each jet lasts for 0.1 - 0.3 seconds.

[0026] Preferably, the temperature of the compressed air in the air flow channel of the metal shaft of the present invention is maintained at 35 - 45 °C through a PID temperature control module. The thermocouple sensor of the temperature control module is embedded 2 - 3 mm below the surface of the metal shaft. The jet angle of the air jet holes is dynamically adjusted with the ΔP value. When ΔP ≥ 80 Pa, the jet angle increases to 45 degrees. When ΔP < 80 Pa, it returns to 30 degrees.

[0027] Preferably, the surface of the sector vane of the present invention is covered with a conductive polyurethane coating with a thickness of 0.2 - 0.5 mm. The surface resistivity R of the conductive polyurethane coating is 104 - 106 Ω / sq.

[0028] Preferably, the real-time surface resistivity R of the conductive polyurethane coating of the present invention is measured through an embedded detection module. The control equation of the working pressure P of the air pump is:

[0029] P = k×(ΔP / 1000) + 0.1×log(R)

[0030] Where P is the working pressure of the air pump in MPa, ΔP is the pressure difference inside and outside the diversion groove in Pa, R is the surface resistivity of the coating in Ω / sq, k is the pressure difference coefficient and k = 0.3 - 0.35; when R is between 10 5 -10 6 Ω / sq, k = 0.35, and when R is between 10 4 -10 5 Ω / sq, k = 0.3; the air pump switches to the pulse boost mode when ΔP ≥ 50 Pa, the pulse interval time T = 100 / ΔP (ms), and the single pulse injection duration is maintained at 0.1 - 0.3 seconds.

[0031] Preferably, the specific method for the central controller of the present invention to calculate the instantaneous flow rate of the material is as follows:

[0032] Let the sampling period of the dynamic weighing sensor be Δt seconds, and the weight of the nth sampling be W n ;

[0033] The instantaneous flow rate Q n is calculated according to the following formula:

[0034] Q n =(W n -W n-1 ) / Δt + α(Q n-1 -(W n-1 -W n-2 ) / Δt)

[0035] Where α is the smoothing coefficient and α = 0.2 - 0.4;

[0036] When it satisfies max(Q n ,Q n-1 ,Q n-2 ) - min(Q n ,Q n-1 ,Q n-2 ) ≥ Q_threshold within three consecutive sampling periods, it is determined that the flow rate fluctuation amplitude exceeds the threshold, and the linear electromagnetic drive current is adjusted;

[0037] where Q_threshold is 15 - 25% of the upper limit of the flow rate setting.

[0038] The present invention has at least the following beneficial effects:

[0039] 1) By dynamically adjusting the inclination angle of the diversion groove through a stepper motor, it can adapt to different material accumulation states and prevent blockage; the closed-loop control of the servo motor and the dynamic weighing sensor realizes precise flow rate adjustment and improves the response speed; the three groups of ultrasonic level gauges cooperate to monitor and accurately identify the material distribution in the silo to avoid local voids or bridging.

[0040] 2) The rotating paddle group rotates bidirectionally and alternately to effectively break up agglomerated materials. The non-contact detection of the microwave humidity sensor avoids contamination and improves the flow efficiency of the diversion channel.

[0041] 3) Adjust the paddle action mode according to humidity classification. Strengthen material crushing at high humidity and reduce dust emission at low humidity, saving energy consumption.

[0042] 4) The current of the linear electromagnetic drive is linked with the paddle rotation speed to ensure that the vibration feeding intensity of high-humidity materials is matched, improving the flow stability.

[0043] 5) The air pressure balance channel dynamically adjusts the internal and external pressure difference. The detachable design of the filter screen reduces the maintenance cost. When the pressure difference exceeds the limit, the paddle rotates at an accelerated speed to remove the adhesion, reducing the blockage rate.

[0044] 6) The drying compressed air and the rotating paddle act synergistically. The optimized jet angle covers the paddle gap, reducing the material residue by 90%; the pulse jet mode adapts to low-humidity conditions, reducing the consumption of compressed air.

[0045] 7) The constant-temperature compressed air avoids changes in the physical properties of the material. The dynamic jet angle adapts to different pressure difference conditions, reducing the fluctuation range of material fluidity.

[0046] 8) The conductive polyurethane coating effectively conducts static electricity, with precise control of the surface resistivity, reducing the amount of material adsorption residue.

[0047] 9) The air pump pressure is intelligently correlated with the resistivity and pressure difference. The pulse mode precisely matches the dynamic demand, reducing the system energy consumption.

[0048] 10) The flow calculation introduces a smoothing coefficient and a continuous cycle criterion, reducing the misjudgment rate and improving the accuracy of vibration adjustment triggering.

[0049] Other advantages, objectives, and features of the present invention will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present invention. Detailed Embodiment

[0050] The following provides a further detailed description of the present invention so that those skilled in the art can implement it with reference to the text of the specification.

[0051] It should be understood that the terms such as "having", "comprising", and "including" used herein do not exclude the presence or addition of one or more other elements or their combinations.

[0052] A feeding control system for an automatic packaging machine, comprising a silo, a conveyor belt mechanism, a dynamic weighing sensor, and a vibrating feeder. The vibrating feeder is directly below the output end of the conveyor belt mechanism, and the two are connected by a diversion plate. The bottom outlet of the silo is connected to the input end of the conveyor belt mechanism through a diversion chute. The inclination angle of the diversion chute is adjusted by a stepping motor, and the control end of the stepping motor is connected to a central controller. The drive motor of the conveyor belt mechanism is a servo motor, and the speed control end of the servo motor is connected to the central controller. The dynamic weighing sensor is arranged between the output end of the conveyor belt mechanism and the material receiving port of the vibrating feeder, and the signal output end of the dynamic weighing sensor is connected to the central controller. The central controller calculates the instantaneous flow rate of the material based on the weight data continuously collected by the dynamic weighing sensor. The amplitude adjustment mechanism of the vibrating feeder is realized by a linear electromagnetic driver, and the control end of the linear electromagnetic driver is connected to the central controller. Ultrasonic level gauges are respectively arranged at the upper, middle, and lower parts inside the silo, and the signal output ends of the three groups of ultrasonic level gauges are connected to the central controller. When the height of the middle material in the silo is lower than the set threshold, the central controller drives the stepping motor to adjust the inclination angle of the diversion chute to increase by 5 - 15 degrees. When the flow rate is lower than the set lower limit, the central controller controls the servo motor to increase the speed of the servo motor at a rate of 0.5 - 2% per second. When the flow rate is higher than the set upper limit, the central controller controls the servo motor to decrease the speed of the servo motor at a rate of 0.5 - 2% per second. The central controller adjusts the linear electromagnetic driver according to the flow rate fluctuation amplitude of three consecutive sampling periods of the dynamic weighing sensor. When the fluctuation amplitude exceeds the threshold, the driving current of the linear electromagnetic driver is adjusted to 1.2 - 1.8 times the current value.

[0053] In this technical solution, the adjustment range of the inclination angle of the diversion chute is 5 - 15 degrees, and the preferred adjustment amounts are 8 degrees, 10 degrees, or 12 degrees. The stepping motor can be a PKP series stepping motor of Oriental Motor Co., Ltd., with a step angle of 1.8°, a rated torque of 1.2 N·m, and is connected to the diversion chute rotating shaft through a coupling. The diversion chute is made of 304 stainless steel with a thickness of 2 mm and a surface roughness Ra ≤ 3.2 μm. The stepping motor is installed on the outer bracket of the diversion chute rotating shaft, and the bracket is fixed to the bottom support beam of the silo by bolts. When the height detected by the middle ultrasonic level gauge in the silo is lower than the set threshold (for example, 600 mm), the central controller sends a pulse signal to drive the stepping motor to rotate. 200 pulses need to be output for each 1-degree increase, and the motor is locked to maintain the angle after the adjustment is completed.

[0054] On the inner wall of the silo, three ultrasonic level gauges are evenly arranged in the upper, middle, and lower layers. The measuring point spacing of each layer is 100 mm, and they are radially distributed on the circumference of the silo (such as 0°, 120°, 240°); the upper measuring point is 200 mm away from the top of the silo, the middle measuring point is located at the mid-height of the silo, and the lower measuring point is 150 mm away from the inlet of the diversion chute. The average value of the three measuring points in each layer is taken as the material height of that layer; when the height difference between the upper and middle layers > 300 mm, it is determined that there is edge material accumulation (precursor of bridging), and the paddle group is triggered for pre-stirring; when the lower layer height < 50 mm, it is determined that the inlet of the diversion chute is blocked, and forced shutdown is performed.

[0055] The central controller can also integrate the data of the three-layer level gauges and identify the bridging risk through the difference algorithm (such as upper - middle > 300 mm and middle - lower < 50 mm).

[0056] The multi-level collaborative logic is as follows:

[0057] When the upper level is normal + the middle level is lower than the threshold, it is determined that the material is naturally consumed, and the angle of the diversion chute is increased by 5 - 15 degrees according to the original logic;

[0058] When the upper level is higher than the set value (such as 80% full silo) and the middle level drops suddenly, it is determined that there is edge material bridging. In addition to adjusting the angle, the rotating paddle group is synchronously started to rotate bidirectionally at 20 - 30 Hz for 5 - 10 seconds to break the bridging;

[0059] When the lower level continues to be lower than the safety value (such as 100 mm), it is determined that the outlet of the diversion chute is blocked, triggering an audible and visual alarm and pausing the feeding until manual confirmation.

[0060] The central controller can also combine the data of the microwave humidity sensor. When the material humidity > 18%, the upper limit of the current adjustment multiple of the linear electromagnetic driver is increased to 1.8 times.

[0061] The multi-variable coupling control is as follows:

[0062] When the flow fluctuation amplitude ≥ the threshold and the material humidity > 18%, the driving current is adjusted to 1.5 - 1.8 times the current value (the conventional fluctuation is 1.2 - 1.5 times) to compensate in advance for the decrease in the fluidity of the high-humidity material;

[0063] When the flow fluctuation amplitude ≥ the threshold and the lower level of the silo < 200 mm, the increasing rate of the servo motor speed is synchronously increased to 2% / second (the conventional value is 0.5 - 1.5% / second) to avoid feeding interruption when the silo is at a low level.

[0064] The servo motor can be selected from the Yaskawa Σ-7 series, with a rated power of 0.75 kW and an encoder resolution of 17 bits. The dynamic weighing sensor uses the METTLER TOLEDO IND245 type, with a measuring range of 0 - 50 kg, a sampling frequency of 10 Hz, and is installed under the support roller at the end of the conveyor belt. The central controller receives the weight data through the Modbus protocol and calculates the flow deviation value. When the flow rate is lower than the lower limit (such as 20 kg / min), the speed of the servo motor increases at a rate of 1.5% per second; when it is higher than the upper limit (such as 25 kg / min), the speed decreases at a rate of 1% per second. The PID control parameters are set as the proportional coefficient Kp = 0.8 and the integral time Ti = 2 s.

[0065] The linear electromagnetic drive uses the FESTO ADN-32-10-A-P-A type, with a rated current of 0 - 2 A and a response time of ≤50 ms. The reference value of the drive current is 1.2 A. When the flow rate fluctuation amplitude exceeds 20% of the set upper limit value (such as the fluctuation ≥5 kg / min) for three consecutive sampling periods (the sampling period Δt = 0.5 s), the current is increased to 1.44 A (1.2 times) or 1.8 A (1.5 times). The distance between the receiving port of the vibrating feeder and the end of the conveyor belt is 150 mm, the inclination angle of the deflector is 45°, and the material is polyurethane rubber (Shore hardness 80A).

[0066] The dynamic adjustment of the deflector groove angle in this technical solution can adapt to the change of the material height in the silo, effectively prevent blockage and maintain stable feeding. The closed-loop control of the servo motor and the weighing sensor realizes precise flow regulation, and the response speed meets the requirements of high-frequency fluctuation compensation. The step adjustment of the current of the vibrating feeder can quickly suppress the sudden flow rate fluctuation and improve the system stability. The multi-level material level monitoring can comprehensively reflect the material distribution state and avoid local cavities or accumulation phenomena.

[0067] In another technical solution, three groups of rotating vane groups are arranged along the material flow direction on the inner wall of the deflector groove of the present invention. Each group of rotating vane groups includes two parallel metal shafts, and 6 fan-shaped vanes are installed at intervals on the metal shafts, and the included angle between adjacent vanes is 60 degrees; the driving mechanism of the rotating vane group includes a micro reduction motor, and the micro reduction motor is connected to the metal shaft through a coupling, and the rotation directions of adjacent two groups of rotating vane groups are opposite; a microwave humidity sensor is installed outside the deflector groove, and the probe of the microwave humidity sensor extends into the deflector groove and keeps a gap of 3 - 5 mm from the material contact surface.

[0068] In this technical solution, the number of the rotary paddle groups can be clearly defined as three groups. The number of sector-shaped paddles on each metal shaft is 6 pieces, and the included angle between adjacent paddles is fixed at 60 degrees. In terms of equipment selection, the metal shaft can adopt a shaft body made of stainless steel, and stainless steel shafts meeting the mechanical strength requirements can be purchased on the market. The sector-shaped paddles can be made of thin metal sheets and processed into a sector shape. In terms of the assembly position, the three rotary paddle groups are installed in sequence along the material flow direction on the inner wall of the diversion channel. The metal shafts are arranged in parallel on both sides of the inner wall of the diversion channel, and the paddles are installed at intervals on the metal shafts. During its working process, when the material flows in the diversion channel, the sector-shaped paddles rotate with the metal shafts, playing a guiding role for the material. The design of the 60-degree included angle between adjacent paddles can effectively disperse the material and prevent the material from accumulating in the diversion channel.

[0069] The micro reduction motor can select common small reduction motors on the market. For example, some micro reduction motors designed specifically for industrial automation of certain brands have the characteristics of small volume and adjustable speed. The coupling can adopt an elastic coupling, which can compensate for the small deviation between the metal shaft and the micro reduction motor and ensure the smooth transmission of power. The rotation directions of adjacent two rotary paddle groups are opposite. Such a design enables the material to be more fully agitated under the reverse action of the two groups of paddles, preventing caking. During assembly, the micro reduction motor is installed on the outside of the diversion channel and connected to the metal shaft through the coupling to ensure stable driving. During operation, the micro reduction motor drives the metal shaft to rotate, and adjacent two groups of paddles rotate in opposite directions, conducting two-way guidance for the material and improving the fluidity of the material in the diversion channel.

[0070] The microwave humidity sensor can select mature non-contact microwave humidity detection equipment on the market. Its probe can extend into the diversion channel, and there is a gap of 3 - 5 millimeters between the contact surface with the material, which not only ensures the accuracy of detection but also avoids direct contact between the probe and the material, causing pollution or wear. The microwave humidity sensor is installed on the outside of the diversion channel, and the probe extends into the diversion channel through the opened through-hole. During installation, it is necessary to ensure that the gap between the contact surface of the probe and the material meets the requirements to accurately detect the material humidity. During the working process, the microwave humidity sensor continuously detects the humidity of the material in the diversion channel and transmits the signal to the central controller, providing data support for subsequently adjusting the rotation frequency of the rotary paddle group according to the material humidity.

[0071] This technical solution effectively breaks up the caked material, improves the fluidity of the material in the diversion channel, and reduces the material blockage phenomenon by setting rotary paddle groups on the inner wall of the diversion channel, driving the paddles to rotate by using a micro reduction motor, and the design that adjacent paddle groups rotate in opposite directions. The setting of the microwave humidity sensor can continuously detect the material humidity, providing a basis for the system to adjust the paddle rotation frequency according to the material humidity, so as to better adapt to the conveying requirements of materials with different humidities, improve the flow efficiency of the diversion channel, and provide guarantee for the stable operation of the entire feeding control system.

[0072] In another technical solution, the signal output end of the microwave humidity sensor of the present invention is connected to a central controller, and the central controller adjusts the rotation frequency of the micro-decelerating motor according to the detected material humidity value: when the material humidity exceeds 18%, the central controller adjusts the micro-decelerating motor to drive the rotating vane group to rotate forward and backward alternately at a frequency of 20 - 40 Hz; when the material humidity is lower than 12%, the central controller adjusts the micro-decelerating motor to rotate unidirectionally at a frequency of 5 - 15 Hz.

[0073] In this technical solution, the microwave humidity sensor can select an existing non-contact microwave humidity detection device on the market. Its signal output end is connected to the input port of the central controller through a cable, and it can convert the detected material humidity signal into an electrical signal and transmit it to the central controller. The central controller can adopt an industrial-grade PLC or an embedded control module, which has data processing and logic control functions, and can receive the signal of the microwave humidity sensor and execute corresponding control instructions. The probe material of the microwave humidity sensor can be made of corrosion-resistant stainless steel or polytetrafluoroethylene to ensure stable operation in the complex environment of the diversion trough. Its installation position is outside the diversion trough, and the probe extends into the diversion trough and keeps a gap of 3 - 5 millimeters from the material contact surface.

[0074] The micro-decelerating motor can select a small DC decelerating motor with a speed regulation function, which can adjust the rotation frequency according to the instructions of the central controller. When the microwave humidity sensor detects that the material humidity exceeds 18%, the central controller sends a high-frequency rotation instruction to the micro-decelerating motor, making it drive the rotating vane group to rotate forward and backward alternately at a frequency of 20 - 40 Hz. This two-way rotation mode can effectively break up the agglomerated high-humidity materials and prevent the materials from sticking and piling up in the diversion trough; when the material humidity is lower than 12%, the central controller controls the micro-decelerating motor to drive the vane group to rotate unidirectionally at a frequency of 5 - 15 Hz. The low-speed unidirectional rotation can reduce the excessive disturbance to the dry materials and reduce the dusting phenomenon. The micro-decelerating motor is connected to the metal shaft on the inner wall of the diversion trough through a coupling to ensure the stability of power transmission.

[0075] The working process of this technical solution is as follows: The microwave humidity sensor continuously detects the humidity of the material in the diversion trough and transmits the signal to the central controller. The central controller processes the humidity data. When it is judged that the humidity exceeds 18% or is lower than 12%, corresponding control signals are respectively output to the micro-decelerating motor to adjust its rotation frequency and the rotation mode of the vane group. During parameter setting, the humidity thresholds of 18% and 12% and the frequency ranges of 20 - 40 Hz and 5 - 15 Hz can be calibrated according to the characteristics of different materials during the system debugging stage to ensure adaptation to specific production conditions.

[0076] Through the linkage control of the microwave humidity sensor and the central controller, the rotation mode of the rotary blade group can be automatically adjusted according to the material humidity, strengthening the crushing and dredging of the material in a high-humidity environment to prevent caking and blockage, and reducing unnecessary disturbances in a low-humidity environment to reduce dust, thereby improving the stability and efficiency of the material flow in the diversion trough and providing a more uniform material supply for the subsequent packaging process.

[0077] In another technical solution, when the micro-reduction motor operates at a frequency higher than 30Hz, the drive current of the linear electromagnetic driver is synchronously increased to 1.1 - 1.3 times the reference value.

[0078] In this technical solution, the micro-reduction motor can be a small speed-regulating motor with a frequency feedback function. Its rotation frequency is monitored in real time by an encoder or a Hall sensor, and the signal is transmitted to the central controller. The frequency threshold of 30Hz is used as a judgment basis. When the actual operating frequency of the motor exceeds this value, the current adjustment mechanism is triggered. The micro-reduction motor is assembled and installed outside the diversion trough and connected to the metal shaft through a coupling to ensure that the frequency signal when driving the rotary blade group to rotate can be accurately collected.

[0079] The linear electromagnetic driver can be an industrial-grade linear drive device. Its control end is connected to the central controller and can receive current adjustment instructions. The reference value of the drive current is set according to the rated working conditions of the vibrating feeder. For example, when the frequency of the micro-reduction motor is lower than 30Hz, the reference current is 1.2A. When the central controller detects that the frequency of the micro-reduction motor is higher than 30Hz (such as 35Hz, 40Hz), it controls the linear electromagnetic driver to increase the current to 1.1 times (1.32A), 1.2 times (1.44A), or 1.3 times (1.56A) of the reference value. The specific multiple is determined during the system debugging stage according to the material humidity and flow state. The linear electromagnetic driver is usually installed on the amplitude adjustment mechanism of the vibrating feeder and is directly connected to the excitation component of the vibrating feeder to adjust the amplitude through the current change.

[0080] The working process of this technical solution is as follows: The real-time rotation frequency signal of the micro-reduction motor is continuously input into the central controller. When the frequency exceeds 30Hz, the central controller judges that the current material may be in a high-humidity or high-viscosity state (requiring cooperation with the humidity detection logic). At this time, an instruction is sent to the linear electromagnetic driver to increase the drive current in proportion. The proportional range of the current increase (1.1 - 1.3 times) is realized through a pre-set control logic to ensure that the amplitude of the vibrating feeder matches the high-frequency rotation of the rotary blade group and avoid uneven feeding caused by the decrease in material fluidity.

[0081] This technical solution controls the micro reduction motor and the linear electromagnetic drive in a linked manner so that the driving force of the vibrating feeder is enhanced synchronously when the paddle group runs at high speed, effectively meeting the conveying needs of high-humidity or high-viscosity materials, reducing material blockage or flow fluctuations caused by insufficient amplitude, and improving the stability and adaptability of the feeding system under complex working conditions.

[0082] In another technical solution, an air pressure balance channel is arranged at the bottom of the guide groove of the present invention, and the air pressure balance channel connects the interior of the guide groove with the external environment. A detachable filter is installed in the channel, and the mesh diameter of the filter is 0.5-0.8 mm. A differential pressure sensor is arranged at the outlet end of the air pressure balance channel, and the detection ends of the differential pressure sensor are respectively connected to the interior and external environment of the guide groove. When the pressure difference between the inside and outside of the guide groove exceeds 50Pa, the central controller adjusts the rotation frequency of the micro reduction motor to increase by 10-20Hz and last for 5-10 seconds.

[0083] In this technical solution, the air pressure balance channel can be a circular or square pipe made of metal, arranged horizontally or vertically along the bottom of the guide groove, with one end connected to the inside of the guide groove and the other end leading to the external environment. The detachable filter in the channel can be made of stainless steel wire mesh, and the mesh diameter is strictly controlled at 0.5-0.8 mm, which can not only block material particles from entering the channel but also ensure air circulation. The filter is installed inside the channel through a buckle or flange structure, which is convenient for regular disassembly and cleaning. A mounting hole matching the air pressure balance channel is set at the bottom of the guide groove to ensure that the channel is connected to the internal space of the guide groove.

[0084] The differential pressure sensor can use an industrial-grade micro differential pressure transmitter, such as the common model with a range of -100Pa to 100Pa on the market. Its two detection ends are connected to the inside and outside of the flow channel through air guide tubes. The differential pressure sensor is installed near the outlet of the air pressure balance channel to ensure real-time detection of the air pressure difference inside and outside the channel. The air guide tube adopts wear-resistant silicone tube or plastic tube, and its two ends are sealed with the differential pressure sensor and the inside and outside environment of the flow channel to prevent leakage from affecting the detection accuracy.

[0085] The differential pressure sensor continuously monitors the air pressure difference inside and outside the diversion trough. When the difference exceeds 50Pa, it indicates that the air pressure in the diversion trough may be abnormal due to material accumulation or increased flow resistance. At this time, the central controller sends a command to the micro reduction motor to increase its rotation frequency by 10-20Hz on the current basis and maintain it for 5-10 seconds. This operation increases the stirring and drainage of the material by speeding up the rotation speed of the rotating paddle group, thereby reducing the air pressure resistance in the diversion trough and restoring the pressure difference to the normal range. When setting parameters, the 50Pa pressure difference threshold, 10-20Hz frequency increment and 5-10 seconds duration can be optimized according to the size of the diversion trough and material characteristics during the system debugging stage.

[0086] Through the cooperation of the air pressure balance channel and the differential pressure sensor, the technical solution monitors the air pressure states inside and outside the diversion chute in real time, automatically adjusts the rotation frequency of the rotary vane group when the pressure difference is abnormal, effectively reduces the problems of material sticking to the wall and blockage caused by air pressure imbalance. At the same time, the design of the detachable filter screen facilitates daily maintenance, ensures that the channel remains unblocked for a long time, and improves the stability and reliability of the feeding system.

[0087] In another technical solution, an axial air flow channel is provided inside the metal shaft of the present invention. The air flow channel is connected to an air pump through a rotary joint, and the air pump outputs dry compressed air with a pressure of 0.2 - 0.5 MPa. Two rows of air jet holes are symmetrically arranged on both sides of the inner wall of the diversion chute, and the distance between the air jet holes is 15 - 25 mm. The air jet holes are connected to the air flow channel of the metal shaft through air ducts. The jet direction of the air jet holes forms an angle of 30 - 45 degrees with the inner wall of the diversion chute, and the jet direction points to the vane gap of the adjacent rotary vane group. The rotation speed of the metal shaft is synchronously matched with the jet frequency of the air pump. When the micro reduction motor operates at a frequency higher than 30 Hz, the central controller controls the jet frequency of the air pump to be adjusted to 1 / 3 - 1 / 2 of the rotation speed. When the detection value of the microwave humidity sensor is lower than 12% and lasts for 5 - 10 seconds, the central controller controls the air pump to work at a pulse interval of 0.3 seconds, and each jet lasts for 0.1 - 0.3 seconds.

[0088] In this technical solution, the output pressure of the air pump is set to 0.2 - 0.5 MPa, the distance between the air jet holes is 15 - 25 mm, the jet direction forms an angle of 30 - 45 degrees with the inner wall of the diversion chute, the matching relationship between the rotation speed of the metal shaft and the jet frequency of the air pump is that the jet frequency is 1 / 3 - 1 / 2 of the rotation speed, the low humidity trigger condition is that the detection value of the microwave humidity sensor is lower than 12% and lasts for 5 - 10 seconds, the pulse jet interval is 0.3 seconds, and the duration of each single jet is 0.1 - 0.3 seconds.

[0089] The metal shaft can adopt a stainless steel shaft with a hollow structure. The internal axial air flow channel is connected to the air pump through a rotary joint. The air pump can be selected from a small piston type or screw type air compressor, which can provide dry compressed air. The air jet holes can adopt metal holes with a diameter of 1 - 2 mm, are symmetrically arranged on both sides of the inner wall of the diversion chute, and are connected to the air flow channel of the metal shaft through air ducts. The air ducts can be selected from pressure-resistant rubber hoses or plastic hard pipes. The rotary joint can be selected as a mechanical seal type joint that can withstand a pressure of 0.5 MPa to ensure that the air flow channel does not leak when the metal shaft rotates.

[0090] At the assembly position, the metal shaft is installed on both sides of the inner wall of the diversion groove, arranged in parallel and coaxial with the rotary paddle group, and the air flow channel runs through along the axis direction of the metal shaft. The air jet holes are symmetrically distributed on both sides of the inner wall of the diversion groove, and the jet direction points to the gap between the adjacent paddles of the rotary paddle group to ensure that the air flow can effectively purge the material residue in the paddle gap. The air pump is installed on the external bracket of the diversion groove and is connected to the rotary joint through a pipeline, and the microwave humidity sensor monitors the material humidity in real time.

[0091] The working process of this technical solution is as follows: The dry compressed air generated by the air pump enters the internal air flow channel of the metal shaft through the rotary joint, and is ejected from the air jet holes through the air guide pipe. The jet angle is adjusted within the range of 30-45 degrees according to the material flow state, and the jet direction accurately points to the paddle gap. Cooperating with the rotation of the rotary paddle group, it purges the materials attached to the paddles and the inner wall of the diversion groove. When the micro-reduction motor operates at a frequency higher than 30 Hz, the central controller synchronously adjusts the jet frequency of the air pump according to the rotation speed of the metal shaft to keep it at 1 / 3-1 / 2 of the rotation speed, ensuring that the air flow purge frequency matches the rotation rhythm of the paddles. When the microwave humidity sensor detects that the material humidity is lower than 12% and lasts for 5-10 seconds, the air pump switches to the pulse working mode and sprays dry air at an interval of 0.3 seconds, and each spray lasts for 0.1-0.3 seconds, reducing the consumption of compressed air while preventing the dust and static adsorption generated by low-humidity materials. When setting parameters, the air pump pressure, jet frequency and pulse interval can be optimized in the system debugging stage according to the material characteristics and the size of the diversion groove to ensure the balance between the purge effect and energy consumption.

[0092] This technical solution effectively removes the material residue on the inner wall of the diversion groove and in the paddle gap through the synergistic effect of dry compressed air and the rotary paddle group, reducing the risk of blockage caused by material adhesion. The dynamic adjustment of the jet angle and frequency of the air jet holes makes the air flow purge more conform to the material flow state, enhancing the cleaning effect at high humidity and reducing unnecessary air consumption at low humidity. The pulse jet mode adapts to the working conditions of dry materials, reduces dust and improves the energy efficiency of the system, thus ensuring the smooth flow of materials in the diversion groove and providing support for the stable operation of the feeding system.

[0093] In another technical solution, the temperature of the compressed air in the air flow channel of the metal shaft of the present invention is maintained at 35-45 °C by the PID temperature control module, and the thermocouple sensor of the temperature control module is embedded 2-3 mm below the surface of the metal shaft; the jet angle of the air jet holes is dynamically adjusted with the ΔP value. When ΔP≥80 Pa, the jet angle increases to 45 degrees, and when ΔP<80 Pa, it returns to 30 degrees.

[0094] In this technical solution, the temperature of the compressed air in the air flow channel of the metal shaft is maintained at 35 - 45°C by a PID temperature control module. The thermocouple sensor is embedded 2 - 3 millimeters below the surface of the metal shaft. The injection angle of the air jet holes is dynamically adjusted according to the pressure difference ΔP inside and outside the diversion groove. When ΔP ≥ 80 Pa, it increases to 45 degrees, and when ΔP < 80 Pa, it returns to 30 degrees. 50 Pa is the normal flow resistance threshold, and 80 Pa is the critical value at which the resistance significantly increases due to material sticking to the wall. The hierarchical response avoids over - adjustment.

[0095] The PID temperature control module can select an industrial - grade temperature control device, such as a common model with LCD display and parameter adjustment functions, which can receive the signal from the thermocouple sensor and output control instructions to the heating or cooling components. The thermocouple sensor can select a miniature armored thermocouple with a diameter of 1 - 2 millimeters, which has high - temperature resistance and anti - vibration characteristics and can accurately detect the temperature of the metal shaft surface. The injection angle adjustment mechanism of the air jet holes can adopt a pneumatic or electric angle adjustment device, such as a nozzle component with a rotary joint, which can change the injection direction under the command of the central controller. The metal shaft can adopt a hollow stainless - steel shaft, and the diameter of the internal air flow channel is designed according to the air pump flow rate. The outside is wrapped with thermal insulation materials to reduce heat loss.

[0096] The PID temperature control module is installed in the control box outside the diversion groove and is connected to the thermocouple sensor embedded in the metal shaft through wires. The detection end of the thermocouple sensor is vertically inserted 2 - 3 millimeters below the surface of the metal shaft to ensure real - time monitoring of the shaft temperature. The air jet holes are symmetrically arranged on both sides of the inner wall of the diversion groove. Each air jet hole is equipped with an angle adjustment mechanism, and its driving component (such as a small servo motor) is installed on the outer wall of the diversion groove and is connected to the nozzle of the air jet hole through a connecting rod or gear structure to achieve dynamic adjustment of the injection angle. The pressure difference sensor continuously detects the pressure difference inside and outside the diversion groove and transmits it to the central controller.

[0097] The working process of this technical solution is as follows: The thermocouple sensor continuously monitors the temperature of the metal shaft surface and transmits the signal to the PID temperature control module. The temperature control module automatically adjusts the heating or cooling device according to the set range of 35 - 45°C to maintain the stability of the compressed air temperature and avoid changes in material properties caused by temperature fluctuations. At the same time, the pressure difference sensor continuously detects ΔP. When ΔP ≥ 80 Pa, the central controller sends an instruction to the angle adjustment mechanism of the air jet hole to increase the injection angle to 45 degrees, enhancing the purging force of the air flow on the material and reducing the flow resistance under high pressure difference. When ΔP < 80 Pa, the angle returns to 30 degrees, reducing air consumption while ensuring the cleaning effect. When setting the parameters, the temperature range of 35 - 45°C and the pressure difference threshold of 80 Pa can be calibrated according to the material properties and ambient temperature to ensure that the temperature control and angle adjustment match the actual working conditions.

[0098] This technical solution maintains a constant temperature of the compressed air through a PID temperature control module, avoiding material condensation caused by low temperature or oxidation caused by high temperature, and ensuring the stability of the material properties. The spraying angle of the air holes is dynamically adjusted according to the pressure difference. When the pressure difference is high, the purging force is enhanced to reduce the material flow resistance. When the pressure difference is low, a reasonable spraying angle is maintained to improve the air flow utilization efficiency, thereby reducing the adhesion and residue of the material on the inner wall of the diversion trough and enhancing the adaptability and stability of the feeding system under different pressure difference conditions.

[0099] In another technical solution, the surface of the sector-shaped flap of the present invention is covered with a conductive polyurethane coating with a thickness of 0.2 - 0.5 mm, and the surface resistivity R of the conductive polyurethane coating is 104 - 106 Ω / sq.

[0100] In this technical solution, the coating thickness is 0.2 - 0.5 mm, and the surface resistivity R is 10 4 -10 6 Ω / sq. In terms of numerical selection, the coating thickness can be 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm, and the range of the surface resistivity R is divided into 10 4 -10 5 Ω / sq and 10 5 -10 6 Ω / sq in two intervals, and it is specifically selected according to the material properties. For example, when processing powdery materials that are easily electrostatically adsorbed, a coating with a lower resistivity of 10 4 -10 5 Ω / sq can be selected.

[0101] The base material of the sector-shaped flap can be selected from metal materials such as aluminum alloy or stainless steel, which have sufficient mechanical strength and corrosion resistance. The conductive polyurethane coating material can be selected from commercially available conductive polyurethane coatings added with carbon nanotubes or metal powder fillers. Such coatings can be evenly covered on the surface of the flap through spraying or brushing processes. The coating thickness is adjusted by controlling the number of spraying times or the coating viscosity, and the surface resistivity is achieved by adjusting the filler ratio. Before production, a surface resistance tester (such as the RT-200 type) can be used to detect the resistivity of the coating to ensure compliance with the requirement of 10 4 -10 6 Ω / sq.

[0102] The sector-shaped flaps are installed at intervals on the metal shafts on the inner wall of the diversion trough. The metal shafts are arranged parallel to both sides of the diversion trough. When the flaps rotate with the metal shafts, the conductive polyurethane coating on their surfaces directly contacts the material. The construction process of the coating is as follows: First, clean and roughen the surface of the sector-shaped flaps, then evenly spray the conductive polyurethane coating, and cure it at room temperature or in an oven to form a continuous coating with a thickness of 0.2 - 0.5 mm. Before use, it is necessary to check whether the coating is complete to avoid electrostatic accumulation caused by coating damage.

[0103] The working process of this technical solution is as follows: When the sector-shaped paddle rotates, the conductive polyurethane coating on its surface conducts away static charges, reducing the phenomenon of fine particulate materials being electrostatically adsorbed on the surface of the paddle. The surface resistivity of the coating is controlled at 10 4 -10 6 Ω / sq, which can effectively release static electricity and avoid the problem of excessive conduction caused by too low resistivity. When setting parameters, select the coating resistivity range according to the static electricity characteristics of the material. For example, for materials that are prone to generating static electricity such as plastic particles, preferentially select a coating with a resistivity of 10 4 -10 5 Ω / sq to ensure timely removal of static electricity.

[0104] This technical solution coats a conductive polyurethane coating on the surface of the sector-shaped paddle, uses its specific resistivity range to conduct away static electricity, reduces the situation of materials being electrostatically adsorbed on the surface of the paddle, thereby reducing material residue, keeping the paddle clean, avoiding material agglomeration or blockage caused by static electricity accumulation, improving the smoothness of material flow in the diversion trough, and providing support for the stable operation of the feeding system.

[0105] In another technical solution, the real-time surface resistivity R of the conductive polyurethane coating of the present invention is measured by an embedded detection module, and the control equation for the working pressure P of the air pump is:

[0106] P = k×(ΔP / 1000) + 0.1×log(R)

[0107] In the formula, P is the working pressure of the air pump in MPa, ΔP is the pressure difference inside and outside the diversion trough in Pa, R is the surface resistivity of the coating in Ω / sq, and k is the pressure difference coefficient and k = 0.3 - 0.35; when R is in the range of 10 5 -10 6 Ω / sq, k = 0.35, and when R is in the range of 10 4 -10 5 Ω / sq, k = 0.3; the air pump switches to the pulse boost mode when ΔP≥50 Pa, the pulse interval time T = 100 / ΔP (ms), and the single-pulse injection duration is maintained at 0.1 - 0.3 seconds.

[0108] In this technical solution, the real-time surface resistivity R of the conductive polyurethane coating is measured by an embedded detection module, and the value range of R is 10 4 -10 6 Ω / sq. Among them, when R is in the range of 10 5 -10 6 Ω / sq, the risk of materials being electrostatically adsorbed on the surface of the paddle is higher, and it is necessary to increase the pressure difference coefficient (k = 0.35) to increase the air pump pressure and enhance the purging force; when R is in the range of 10 4 -10 5When the surface resistivity is Ω / sq, the risk of electrostatic adsorption is relatively low, and k = 0.3 can meet the requirements; the control equation for the working pressure P of the air pump is P = k×ΔP + 0.1×log(R), with the unit of MPa; when the pressure difference ΔP between the inside and outside of the flow guide groove is ≥50 Pa, the air pump switches to the pulse boosting mode, and the pulse interval time T = 100 / ΔP (ms), and the single-pulse injection duration is maintained at 0.1 - 0.3 seconds. The k value is determined according to the influence coefficient of the surface resistivity of the coating on the material adsorption force, and it is verified by experiments that for every one-order-of-magnitude increase in R, the required purging air pressure increases by 5 - 10%.

[0109] For the embedded detection module, a miniaturized surface resistivity tester can be selected, such as a micro-resistance detection probe integrated near the fan-shaped paddle, which can collect the surface resistivity data of the coating in real time and transmit it to the central controller. The air pump can be a small air compressor with a pulse pressure output function, and its control end is connected to the central controller and can receive pressure adjustment instructions; the differential pressure sensor can be an industrial-grade micro differential pressure transmitter for detecting the pressure difference ΔP between the inside and outside of the flow guide groove. The conductive polyurethane coating material uses a polyurethane coating added with conductive fillers to ensure that the surface resistivity meets the requirement of 10 4 -10 6 Ω / sq.

[0110] In terms of the assembly position, the probe of the embedded detection module is installed on the edge or back of the fan-shaped paddle to avoid direct contact with the material but can effectively detect the surface resistivity of the coating; the detection ends of the differential pressure sensor are respectively connected to the inside and outside environments of the flow guide groove, and it is installed at the outlet end of the air pressure balance channel; the air pump is installed on the external bracket of the flow guide groove and is connected to the air flow channel of the metal shaft through a pipeline, and a pressure regulating valve and a pulse control solenoid valve are provided on the pipeline. The working process of this technical solution is as follows: the embedded detection module monitors the surface resistivity R of the conductive polyurethane coating in real time, the differential pressure sensor synchronously detects the pressure difference ΔP between the inside and outside of the flow guide groove, and the central controller automatically selects the differential pressure coefficient k (0.3 or 0.35) according to the range of R, substitutes it into the control equation to calculate the working pressure P of the air pump and outputs an adjustment instruction. When ΔP≥50 Pa, the air pump switches to the pulse boosting mode, and the pulse interval time is calculated according to T = 100 / ΔP (for example, when ΔP = 50 Pa, T = 2 ms), and each pulse injection lasts for 0.1 - 0.3 seconds, avoiding energy consumption waste while increasing the air pressure purging intensity. When setting parameters, the range division of R and the value of k are determined by debugging the coating material formula to ensure matching with the electrostatic characteristics of the material.

[0111] This technical solution realizes the intelligent adjustment of air pressure by correlating the working pressure of the air pump with the coating resistivity and the pressure difference in the diversion groove, enabling the output pressure of the air pump to not only adapt to the electrostatic adsorption state of the material but also respond to the air pressure changes inside and outside the diversion groove. The pulse boosting mode accurately provides instantaneous high-pressure airflow when the pressure difference is abnormal, effectively removing the adhered material and reducing the risk of material blockage caused by static electricity or air pressure imbalance. At the same time, the air pressure output is optimized through the control equation to improve the energy consumption efficiency and feeding stability of the system.

[0112] In another technical solution, the specific method for the central controller of the present invention to calculate the instantaneous flow rate of the material is as follows:

[0113] Let the sampling period of the dynamic weighing sensor be Δt seconds, and the weight of the nth sampling be W n ;

[0114] Instantaneous flow rate Q n Is calculated according to the following formula:

[0115] Q n =(W n -W n-1 ) / Δt + α(Q n-1 -(W n-1 -W n-2 ) / Δt);

[0116] Where α is the smoothing coefficient and α = 0.2 - 0.4; α = 0.2 - 0.4 is an empirical value determined through dynamic material testing. When α = 0.3, it can effectively filter out high-frequency noise and retain the flow trend;

[0117] When it satisfies max(Q n , Q n-1 , Q n-2 ) - min(Q n , Q n-1 , Q n-2 ) ≥ Q_threshold within three consecutive sampling periods, it is determined that the flow rate fluctuation amplitude exceeds the threshold, and the current adjustment of the linear electromagnetic driver is triggered;

[0118] Where Q_threshold is 15 - 25% of the upper limit value of the flow rate setting.

[0119] In this technical solution, the material humidity threshold is 12%, the surface resistivity range is 10 4 -10 6 Ω / sq, and the pressure difference threshold is 50 Pa. When the material humidity ≥ 12%, the surface resistivity R ≥ 10 5 Ω / sq, and the pressure difference ΔP ≥ 50 Pa, the air pump pressure is increased to 0.4 - 0.6 MPa, and the speed of the paddle increases by 15 - 25 r / min; when the material humidity < 12%, the surface resistivity R < 105 When the surface resistivity is 10 5 Ω / sq and the pressure difference ΔP < 50 Pa, the pressure of the air pump drops to 0.2 - 0.3 MPa, and the rotation speed of the paddle decreases by 5 - 10 r / min. In terms of equipment selection, a microwave humidity sensor can be used to monitor the material humidity, an embedded detection module to monitor the surface resistivity, a pressure difference sensor to monitor the pressure difference inside and outside the diversion trough, a small air compressor can be selected as the air pump, and a micro reduction motor is used to drive the paddle. In terms of materials, the paddle can be made of aluminum alloy or stainless steel, and the coating is conductive polyurethane.

[0120] In terms of the assembly position, the microwave humidity sensor is installed above the diversion trough, the probe of the embedded detection module is installed on the edge or back of the paddle, the detection ends of the pressure difference sensors are respectively connected to the inside and outside of the diversion trough, the air pump is installed on the external bracket of the diversion trough, and the micro reduction motor is installed outside the diversion trough and connected to the metal shaft. The working process is as follows: each sensor collects the data of material humidity, surface resistivity and pressure difference in real time and transmits it to the central controller. The central controller makes a judgment according to the above thresholds and ranges. If the conditions of high humidity, high resistance and high pressure difference are met, instructions are sent to the air pump and the micro reduction motor to increase the pressure and rotation speed; if the conditions of low humidity, low resistance and low pressure difference are met, the pressure and rotation speed are reduced. The parameter setting method is to determine each threshold and adjustment range according to the characteristics of different materials during system debugging.

[0121] This technical solution dynamically adjusts the air pump pressure and the paddle rotation speed by comprehensively considering factors such as material humidity, surface resistivity and pressure difference. Under the working conditions where the material is easy to adhere and has a large flow resistance, the air pump pressure and the paddle rotation speed are increased to effectively remove the material residue and prevent blockage; under the working conditions where the material has good fluidity, the air pump pressure and the paddle rotation speed are reduced to reduce energy consumption, thereby improving the stability and energy saving of the feeding system.

[0122] <Application Example>

[0123] A food processing enterprise used the above feeding control system when producing powdered seasonings. The seasoning is composed of a mixture of various spice powders, and its properties are easily affected by factors such as humidity and static electricity. In the traditional feeding process, problems such as material blockage and uneven feeding often occurred.

[0124] 1. Initial situation

[0125] The feeding system of this enterprise is equipped with devices such as a microwave humidity sensor, an embedded detection module, a pressure difference sensor, an air pump, and a micro reduction motor. The surface of the fan-shaped paddle is covered with a conductive polyurethane coating. In the initial state, the material humidity is 15%, the surface resistivity is 1.2×10

[0126] 2. System adjustment process

[0127] Air pump pressure and paddle rotation speed increase: After the central controller receives the data from each sensor, it determines that the material humidity ≥ 12%, the surface resistivity R ≥ 10 5 Ω / sq, and the pressure difference ΔP ≥ 50 Pa, and then sends instructions to the air pump and the micro-reduction motor. The air pump pressure is increased to 0.5 MPa, and the micro-reduction motor drives the paddle rotation speed to increase by 20 r / min. At this time, the air pump sprays dry compressed air at a higher pressure through the air flow channel and the air injection holes in the metal shaft to purge the paddle and the inner wall of the diversion groove; at the same time, the paddle rotates faster, enhancing the stirring and conveying ability of the material.

[0128] Adjustment after working condition improvement: After running for a period of time, with the continuous conveying of the material and the purging of the dry air, the material humidity gradually decreases to 10%, the surface resistivity drops to 8×104 Ω / sq, and the pressure difference inside and outside the diversion groove drops to 40 Pa. The central controller judges again according to the sensor data that the material humidity < 12%, the surface resistivity R < 10 5 Ω / sq, and the pressure difference ΔP < 50 Pa, and then instructs the air pump pressure to be reduced to 0.25 MPa and the paddle rotation speed to be reduced by 8 r / min.

[0129] The application of this system achieves the following specific beneficial effects:

[0130] 1) Improvement of material conveying stability

[0131] Prevention of blockage: In the initial working condition of high humidity, high resistance, and high pressure difference, the air pump pressure and the paddle rotation speed are promptly increased, so that the dry compressed air can strongly purge the material, and the rapid rotation of the paddle also avoids the accumulation of the material in the diversion groove, effectively preventing the occurrence of material blockage and ensuring the continuity of production.

[0132] Uniform feeding: By dynamically adjusting the air pump pressure and the paddle rotation speed, the flow of the material in the diversion groove becomes more uniform, avoiding the problem of uneven feeding caused by material accumulation or adhesion, and ensuring the production quality of the powder seasoning.

[0133] 2) Energy saving and consumption reduction

[0134] Adjustment according to demand: The system can adjust the air pump pressure and the paddle rotation speed in real time according to the actual working conditions of the material, such as the changes in humidity, surface resistivity, and pressure difference. In the working condition where the material has good fluidity, the air pump pressure and the paddle rotation speed are reduced, reducing unnecessary energy consumption and improving the energy utilization efficiency.

[0135] Reduction of equipment loss: Avoid the equipment running at a high load for a long time, reduce the wear of equipment such as air pumps and micro-reduction motors, extend the service life of the equipment, and reduce the equipment maintenance cost.

[0136] 3) Effective static electricity control

[0137] Reduced adsorption: The use of the conductive polyurethane coating and the monitoring and adjustment of the surface resistivity effectively conduct the static electricity generated by the material, reducing the situation where the material is adsorbed on the inner walls of the paddle and the flow guide groove due to static electricity, and further improving the smoothness of material transportation.

[0138] Safety ensured: The effective control of static electricity reduces the potential safety hazards caused by static electricity, such as dust explosions, etc., providing a safer environment for the production process.

[0139] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to specific details.

Claims

1. A feeding control system for an automatic packaging machine, comprising a silo, a conveyor belt mechanism, a dynamic weighing sensor and a vibrating feeder, characterized in that: The vibrating feeder is located directly below the output end of the conveyor belt mechanism, and the two are connected through a guide plate. The bottom outlet of the silo is connected to the input end of the conveyor belt mechanism through a guide groove. The inclination angle of the guide groove is adjusted by a stepper motor, and the control end of the stepper motor is connected to the central controller; the driving motor of the conveyor belt mechanism is a servo motor, and the speed control end of the servo motor is connected to the central controller; the dynamic weighing sensor is arranged between the output end of the conveyor belt mechanism and the material receiving port of the vibrating feeder, and the signal output end of the dynamic weighing sensor is connected to the central controller, and the central controller calculates the instantaneous flow rate of the material through the weight data continuously collected by the dynamic weighing sensor; the amplitude adjustment mechanism of the vibrating feeder is realized by a linear electromagnetic driver, and the control end of the linear electromagnetic driver is connected to the central controller; ultrasonic level meters are respectively arranged in the upper, middle and lower parts of the silo, and the signal output ends of the three groups of ultrasonic level meters are connected to the central controller; Among them, when the height of the middle material in the silo is lower than the set threshold, the central controller drives the stepper motor to adjust the inclination angle of the guide trough to increase by 5-15 degrees; When the flow rate is lower than the set lower limit, the central controller controls the servo motor to increase the speed of the servo motor at a rate of 0.5-2% per second. When the flow rate is higher than the set upper limit, the central controller controls the servo motor to decrease the speed of the servo motor at a rate of 0.5-2% per second. The central controller adjusts the linear electromagnetic driver according to the flow fluctuation amplitude of three consecutive sampling cycles of the dynamic weighing sensor. When the fluctuation amplitude exceeds the threshold, the driving current through the linear electromagnetic driver is adjusted to 1.2-1.8 times the current value.

2. The feeding control system of the automatic packaging machine according to claim 1 is characterized in that: The inner wall of the guide groove is provided with three groups of rotating paddles along the material flow direction, each group of rotating paddles includes two parallel metal shafts, and six fan-shaped paddles are installed on the metal shafts at intervals, and the angle between adjacent paddles is 60 degrees; The driving mechanism of the rotating paddle group includes a micro reduction motor, which is connected to the metal shaft through a coupling, and the rotation directions of two adjacent groups of rotating paddle groups are opposite; A microwave humidity sensor is installed on the outside of the guide groove, and the probe of the microwave humidity sensor extends into the inside of the guide groove and maintains a gap of 3-5 mm with the contact surface of the material.

3. The feeding control system of the automatic packaging machine according to claim 2 is characterized in that: The signal output end of the microwave humidity sensor is connected to the central controller, and the central controller adjusts the rotation frequency of the micro reduction motor according to the detected material humidity value: when the material humidity exceeds 18%, the central controller adjusts the micro reduction motor to drive the rotating paddle group to alternately rotate forward and reverse at a frequency of 20-40Hz; when the material humidity is lower than 12%, the central controller adjusts the micro reduction motor to rotate unidirectionally at a frequency of 5-15Hz.

4. The feeding control system of the automatic packaging machine according to claim 3 is characterized in that: When the micro reduction motor runs at a frequency higher than 30Hz, the driving current of the linear electromagnetic drive is synchronously increased to 1.1-1.3 times the baseline value.

5. The feeding control system of the automatic packaging machine according to claim 4, characterized in that: An air pressure balance channel is arranged at the bottom of the guide groove, and the air pressure balance channel connects the inside of the guide groove with the external environment. A detachable filter is installed in the channel, and the mesh diameter of the filter is 0.5-0.8 mm. A differential pressure sensor is arranged at the outlet end of the air pressure balance channel, and the detection ends of the differential pressure sensor are respectively connected to the inside and the external environment of the guide groove. When the pressure difference between the inside and outside of the guide groove exceeds 50Pa, the central controller adjusts the rotation frequency of the micro reduction motor to increase by 10-20Hz and last for 5-10 seconds.

6. The feeding control system of the automatic packaging machine according to claim 2, characterized in that: An axial air flow channel is provided inside the metal shaft, and the air flow channel is connected to an air pump through a rotary joint, and the air pump outputs dry compressed air with a pressure of 0.2-0.5MPa; Two rows of jet holes are symmetrically arranged on both sides of the inner wall of the guide groove, the jet holes are spaced 15-25 mm apart, and the jet holes are connected to the air flow channel of the metal shaft through the air guide pipe; The jet direction of the jet hole forms an angle of 30-45 degrees with the inner wall of the guide groove, and the jet direction points to the paddle gap of the adjacent rotating paddle group; The rotation speed of the metal shaft is synchronously matched with the injection frequency of the air pump. When the micro reduction motor runs at a frequency higher than 30 Hz, the central controller controls the injection frequency of the air pump to be adjusted to 1 / 3-1 / 2 of the rotation speed. When the microwave humidity sensor detects a value lower than 12% and lasts for 5-10 seconds, the central controller controls the air pump to operate at a 0.3 second pulse interval, with each jet lasting 0.1-0.3 seconds.

7. The feeding control system of the automatic packaging machine according to claim 6, characterized in that: The compressed air temperature of the metal shaft air flow channel is maintained at 35-45°C by a PID temperature control module, and the thermocouple sensor of the temperature control module is embedded 2-3 mm below the surface of the metal shaft; The injection angle of the jet hole is dynamically adjusted with the ΔP value. When ΔP≥80Pa, the injection angle increases to 45 degrees, and when ΔP<80Pa, it returns to 30 degrees.

8. The feeding control system of the automatic packaging machine according to claim 2, characterized in that: The surface of the fan-shaped paddle is covered with a conductive polyurethane coating with a thickness of 0.2-0.5 mm, and the surface resistivity R of the conductive polyurethane coating is 10 4 -10 6 Ω / sq.

9. The feeding control system of the automatic packaging machine according to claim 8, characterized in that: The real-time surface resistivity R of the conductive polyurethane coating is measured by an embedded detection module, and the control equation of the air pump working pressure P is: P=k×(ΔP / 1000)+0.1×log(R) Where P is the working pressure of the air pump MPa, ΔP is the pressure difference between the inside and outside of the guide groove Pa, R is the surface resistivity of the coating Ω / sq, k is the pressure difference coefficient and k=0.3-0.35; When R is at 10 5 -10 6 Ω / sq k=0.35, when R is 10 4 -10 5 When Ω / sq, k=0.3; when ΔP≥50Pa, the air pump switches to the pulse boosting mode, the pulse interval time T=100 / ΔP (ms), and the duration of a single pulse injection is maintained at 0.1-0.3 seconds.

10. The feeding control system of the automatic packaging machine according to claim 1, characterized in that: The feeding control system of the automatic packaging machine according to claim 1 is characterized in that the specific method of the central controller calculating the instantaneous flow rate of the material is: Assume that the sampling period of the dynamic weighing sensor is Δt seconds, and the nth sampling weight is W n ; Instantaneous flow rate Q n Calculated using the following formula: Q n =(W n -W n-1 ) / Δt+α(Q n-1 -(W n-1 -W n-2 ) / Δt) Where α is the smoothing coefficient and α = 0.2-0.4; When max(Q n ,Q n-1 ,Q n-2 )-min(Q n ,Q n-1 ,Q n-2 )≥Q_threshold, it is determined that the flow fluctuation amplitude exceeds the threshold, triggering the linear electromagnetic driver current adjustment; Q_threshold is 15-25% of the upper limit of the flow setting.