High water content corn threshing mechanism based on PLC system

Abstract

The application provides a high-moisture corn threshing mechanism based on a PLC system, and relates to the technical field of agricultural machinery.The device is composed of a power and transmission mechanism, a bridge passing mechanism, a feeding mechanism, a threshing mechanism, a control system and a machine shell.The power and transmission mechanism realizes linkage speed regulation of the whole machine by dynamically adjusting the engine speed.The chain harrow conveying assembly of the bridge passing mechanism stably conveys corn crops.The feeding mechanism ensures continuous supply of crops.The threshing mechanism adopts an optimized longitudinal axial flow threshing cylinder to improve the threshing efficiency and quality.The control system collects data in real time, calculates a blockage risk factor based on the PLC, intelligently adjusts the speed and prevents blockage.The high-moisture corn threshing mechanism based on the PLC system solves the problems of high grain breakage rate, incomplete threshing and blockage caused by manual adjustment of traditional equipment, significantly reduces the operation loss rate and energy consumption, and improves the corn direct harvesting efficiency.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery, and in particular to a high-moisture-content corn threshing mechanism based on a PLC system. Background Technology

[0002] Corn is one of the most widely planted food crops globally, accounting for a significant proportion of total grain planting area. With the continuous development of mechanized corn harvesting technology, direct corn kernel harvesting has become an important development direction for corn harvesting. As a key component of the direct harvesting mode, the corn threshing mechanism's operating parameters and the design of its threshing elements play a decisive role in threshing performance, thus affecting the overall harvesting quality.

[0003] Traditional corn combine harvesters often rely on the driver's experience or simple gear adjustments for speed control, making it difficult to adapt to the physical characteristics of corn in the field in real time. However, during corn harvesting, appropriate harvester speed and the rotational speed of each component are crucial for reducing kernel breakage and threshing rates, while also effectively preventing clogging and keeping fuel consumption low. Therefore, there is an urgent need to develop an intelligent speed-regulating threshing system based on a PLC control system. This system should integrate multi-parameter fusion calculations, continuous speed control, and novel threshing components to overcome the technical bottlenecks in efficient and low-loss corn harvesting, and promote the development of corn harvesting technology towards greater efficiency and intelligence. Summary of the Invention

[0004] The purpose of this invention is to provide a high-moisture-content corn threshing mechanism based on a PLC system, which solves the problems of mismatch between travel speed and field crop characteristics, inaccurate adjustment of threshing parameters, high threshing loss rate, high fuel consumption, and easy clogging in traditional corn combine harvesters.

[0005] To achieve the above objectives, the present invention provides a high-moisture-content corn threshing mechanism based on a PLC system, comprising:

[0006] The power and transmission mechanism includes an engine, an engine output wheel, and a multi-stage pulley. The multi-stage pulley consists of a threshing drum drive pulley, a second feed roller pulley, a first feed roller pulley, a tensioning wheel, a bridge drive wheel, and a bridge drive wheel. The engine is connected to the multi-stage pulley through the engine output wheel, and the operating speed of the feeding mechanism, the bridge mechanism, and the threshing mechanism is synchronously controlled by dynamically adjusting the engine speed.

[0007] The bridging mechanism includes a chain rake conveyor assembly, which consists of a sprocket, a chain, and multiple U-shaped chain rakes, and is used to convey corn crops from the feeding section to the threshing mechanism.

[0008] The feeding mechanism includes a first feeding roller and a second feeding roller. The first feeding roller is provided with a textured rack, a textured screen, a first feeding roller drive shaft and an octagonal metal plate. The second feeding roller is provided with a straight feeding plate, a spiral feeding plate, a second feeding roller shaft and a second feeding roller drive shaft.

[0009] The threshing mechanism includes a longitudinal axial flow threshing drum, which is provided with a threshing drum body, spiral blades, a feeding cone, threshing and kneading teeth, cylindrical toothed rods, a threshing drum shaft, and a threshing drum screen.

[0010] The control system consists of a monitoring system, a controller, and an execution system. The monitoring system collects the operating parameters of the threshing section and the conveying path in real time. The controller, based on a PLC platform, processes and analyzes the collected data and calculates the blockage risk factor. The execution system dynamically adjusts the engine speed and locomotive speed according to the instructions output by the controller.

[0011] Preferably, in the power and transmission mechanism, the multi-stage engine output wheel has a three-stage fixed diameter combination structure, namely 140mm, 180mm, and 220mm;

[0012] When the crop moisture content is in the range of 20% to 25%, the engine output wheel is selected with a diameter of 140mm, which is suitable for low-resistance and light-load conveying and threshing conditions.

[0013] When the crop moisture content is in the range of 25% to 30%, the engine output wheel is selected with a diameter of 180mm for medium load conditions under normal moisture content conditions.

[0014] When the crop moisture content reaches 30% or more, the engine output wheel is selected with a diameter of 220mm to provide greater torque output to adapt to the high humidity and high resistance threshing environment.

[0015] Preferably, the chain rake conveying assembly, power and transmission mechanism of the bridge crossing mechanism are housed within a closed machine housing, which is a metal shell structure.

[0016] The sprockets are installed at both ends of the bridge mechanism and are connected to the bridge drive wheel and bridge transmission wheel through the bridge drive shaft. The chain is installed on the sprockets and multiple U-shaped chain rakes are fixed at equal intervals between the chain to form a closed-loop conveying structure.

[0017] Bearing seats are provided between the bridge drive wheel and the adjacent sprocket, and between the bridge drive wheel and the connected sprocket.

[0018] Preferably, octagonal metal plates are spaced and fitted onto the drive shaft of the first feed roller. A grooved rack is fixed to the corresponding position of the octagonal metal plate by bolts. A grooved screen is installed on the machine housing, located below the first feed roller, and cooperates with the first feed roller to form a crop feeding channel. A slide rail is provided between the grooved screen and the first feed roller to adjust the height gap between the grooved screen and the first feed roller, thereby improving the feeding adaptability under different crop conditions.

[0019] Preferably, one end of the first feed roller drive shaft is fixedly connected to the first feed roller driven wheel, and the first feed roller driven wheel drives the feed roller drive shaft to rotate.

[0020] Preferably, the second feed roller drive wheel is fixedly connected to the outside of the second feed roller shaft, the straight feed plate is uniformly arranged along the axial direction of the second feed roller shaft, and the spiral feed plate is spirally wound on the outer surface of the second feed roller shaft and located at both ends of the straight feed plate.

[0021] Preferably, a feeding cone and a threshing drum shaft are respectively provided at the front and rear ends of the threshing drum body. The feeding cone is provided with spiral blades. Threshing kneading teeth and cylindrical toothed rods are sequentially provided on the threshing drum body along the direction from the feeding cone to the threshing drum shaft. A threshing drum screen is installed at the bottom of the threshing chamber below the threshing drum body.

[0022] The threshing drum has an adjustable tilt angle. An angle adjustment mechanism is provided between the threshing drum body and its support base. The angle adjustment mechanism is controlled by a PLC control system. Its tilt angle adjustment range is 15° to 20°. It can adjust the angle between the drum and the horizontal plane in real time according to the feeding pressure and crop moisture content parameters collected by the monitoring device.

[0023] Preferably, the outer surfaces of the threshing drum body, spiral blades, and feeding cone of the longitudinal axial flow threshing drum are all treated with HVOF sprayed tungsten carbide coating.

[0024] Preferably, the monitoring system includes an ambient humidity sensor and a pressure sensor; the ambient humidity sensor is installed at the front end of the bridge mechanism, and the pressure sensor includes: a first pressure sensor disposed between the bridge mechanism and the first feed roller, and a second pressure sensor and a third pressure sensor disposed at the front and rear sections of the threshing mechanism.

[0025] The monitoring device collects various signals and transmits them to the PLC controller in real time to determine the current operating status and generate control commands to send to the execution system, thereby adjusting the engine power output and vehicle speed.

[0026] Preferably, the formula for calculating the congestion risk factor is as follows:

[0027] R = α × (P) f -P r )+β×Pin +γ×H;

[0028] Where R represents the congestion risk factor, P in H represents the feed pressure, P represents the ambient humidity. f P represents the pressure at the front of the threshing drum. r α represents the pressure at the rear section of the threshing drum, and α, β, and γ all represent system adjustment coefficients.

[0029] Based on the congestion threshold, a speed adjustment command is generated and sent to the cab interface to adjust the engine speed.

[0030] N e =N0-k×max(0,RR) th );

[0031] Where N0 represents the engine base speed, k represents the speed adjustment sensitivity coefficient, and N e R represents the adjusted target engine speed. th This indicates the threshold for blocking risks.

[0032] Therefore, the present invention employs the above-mentioned high moisture content corn threshing mechanism based on a PLC system, and the beneficial technical effects are as follows:

[0033] (1) Improve threshing efficiency and quality.

[0034] Optimized feeding mechanism: The multi-roller structure, with the first and second feeding rollers working together, ensures a continuous and stable supply of crops, allowing corn crops to enter the threshing mechanism more smoothly, reducing blockages and discontinuities during the feeding process, thus providing good preconditions for subsequent threshing operations and improving threshing efficiency.

[0035] Intelligent speed control system: Based on a PLC controller and simulation database, it performs real-time calculations and risk assessments on monitoring data, and achieves anti-blocking control by dynamically adjusting engine speed and locomotive travel speed. This intelligent speed control mechanism can automatically adjust the operating speed of each mechanism according to the actual operating conditions, making the threshing process smoother and more efficient, further improving threshing efficiency and quality.

[0036] (2) Enhance operational stability.

[0037] Multi-stage belt pulley drive: The multi-stage belt pulleys in the power and transmission mechanism are configured with a fixed diameter but multiple gears according to the load requirements of different working units. This allows for reasonable transmission ratio matching of each system submechanism, adapting to the threshing operation needs under different crop moisture contents and load variations. This transmission method ensures the coordinated speed regulation of the entire machine's power system, thereby synchronously controlling the operating speeds of the feeding mechanism, bridge mechanism, and threshing mechanism, ensuring the continuity and stability of the overall operation.

[0038] Monitoring and Early Warning Control: The monitoring device integrates environmental humidity and pressure sensors to collect crop physical parameters and feed load in real time. The signal processing system analyzes the operational status based on sensor data. If a blockage risk is detected, the system automatically sends a deceleration warning signal to the cab, guiding the driver to reduce speed and avoid blockage. This real-time monitoring and early warning control function can promptly detect and prevent potential blockages, enhancing the stability of the operation.

[0039] (3) Reduce operational loss rate and energy consumption.

[0040] Reduce kernel breakage rate: The threshing and kneading teeth are made of thermosetting polyurethane material, which has good elastic modulus, wear resistance and wet working stability. It can reduce damage to kernels while ensuring threshing force, and is particularly suitable for corn harvesting operations with a wide range of moisture content, thereby effectively reducing kernel breakage rate and reducing operation losses.

[0041] Reduce congestion problems: Through optimized structural design, intelligent speed control system and real-time monitoring and early warning functions, this invention can effectively reduce the risk of congestion, avoid operation interruption and repetitive operation caused by congestion, reduce corn loss caused by congestion, and also help reduce the additional energy consumption caused by congestion problems, thereby improving operation efficiency and economy.

[0042] (4) Improve equipment lifespan and reliability.

[0043] Wear-resistant coating treatment: The outer surfaces of the threshing drum body, spiral blades, and feeding cone are treated with HVOF sprayed tungsten carbide coating. This coating has excellent adhesion and adjustable surface roughness, which significantly improves the surface hardness, wear resistance, and friction adjustment ability of the components for corn kernels. It effectively prevents blockage, sliding, or structural damage caused by local over-wearing or surface wear, thereby extending the service life of the equipment and improving its reliability and stability.

[0044] Reasonable structural design and material selection: The cylindrical toothed rod is made of high-strength alloy steel, possessing extremely high hardness and impact resistance. It is specifically designed for supplementary threshing and final removal of stubborn kernels remaining in the later stages of threshing, ensuring thorough threshing while also withstanding significant impact forces, thus improving the equipment's durability. Furthermore, the chain rake conveyor assembly and transmission mechanism of the bridge mechanism are housed within a closed machine casing. The metal casing structure protects the conveying system from external dust, debris, and mechanical damage, facilitating equipment maintenance and cleaning, and further enhancing the equipment's reliability and service life. Attached Figure Description

[0045] Figure 1This is a schematic diagram of a high-moisture-content corn threshing mechanism based on a PLC system.

[0046] Figure 2 A schematic diagram of the power and transmission mechanism;

[0047] Figure 3 This is a schematic diagram of the bridge crossing mechanism;

[0048] Figure 4 This is a schematic diagram of the structure of the first feed roller;

[0049] Figure 5 This is a schematic diagram of the second feed roller.

[0050] Figure 6 This is a schematic diagram of the threshing mechanism.

[0051] Figure Labels

[0052] 1. Power and transmission mechanism; 101. Engine output wheel; 102. Threshing drum drive pulley; 103. Second feed roller pulley; 104. First feed roller pulley; 105. Tensioner wheel; 106. Bridge drive wheel; 107. Bridge drive wheel; 2. Bridge mechanism; 201. U-shaped chain rake; 202. Sprocket; 203. Bearing housing; 204. Chain; 205. Bridge drive shaft; 3. Feeding mechanism; 301. Rack and pinion; 302. Rack and pinion screen; 303. 1. Octagonal metal plate; 304. First feed roller drive shaft; 305. Slide rail; 306. Straight feed plate; 307. Spiral feed plate; 308. Second feed roller shaft; 309. Second feed roller drive shaft; 4. Monitoring device; 5. Machine casing; 6. Threshing mechanism; 601. Threshing drum body; 602. Spiral blades; 603. Feed cone; 604. Threshing and kneading teeth; 605. Cylindrical toothed rod; 606. Threshing drum shaft; 607. Threshing drum screen; 7. Engine. Detailed Implementation

[0053] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0054] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0055] Example 1

[0056] like Figure 1As shown, a high-moisture-content corn threshing mechanism based on a PLC system includes key components such as a power and transmission mechanism 1, a bridge mechanism 2, a feeding mechanism 3, a threshing mechanism 6, a monitoring device 4, a control system, and a machine casing 5. These components work together to effectively solve problems encountered by traditional corn combine harvesters during operation, such as mismatch between travel speed and crop characteristics, inaccurate adjustment of threshing parameters, high threshing loss rate, high fuel consumption, and susceptibility to clogging. This improves corn threshing efficiency, quality, and operational stability, reduces operational loss rate and energy consumption, and simultaneously extends equipment lifespan and reliability.

[0057] like Figure 2 As shown, the power and transmission mechanism 1 is the core power source of the entire threshing mechanism. It mainly includes an engine 7, an engine output pulley 101, and a multi-stage pulley system. The multi-stage pulley system consists of a threshing drum drive pulley 102, a second feed roller pulley 103, a first feed roller pulley 104, a tension pulley 105, a bridge drive pulley 106, and a bridge drive pulley 107. The engine 7 is connected to the multi-stage pulley system via the engine output pulley 101, using belt drive to achieve multi-path distribution and coordinated transmission of the prime mover power. The multi-stage pulley system has a three-stage fixed diameter combination structure. Each set of pulleys is configured with three standard diameters: 140mm, 180mm, and 220mm, suitable for light-load conveying, conventional feeding, and heavy-load threshing mechanisms, respectively. Different diameter combinations create varying transmission ratios, enabling differentiated adaptation of speeds to various system sub-mechanisms. The output power of engine 7 can be dynamically adjusted according to the work load signal fed back from the cab. By adjusting the engine speed, the speed regulation of the whole machine power system can be realized, thereby synchronously controlling the operating speed of feeding mechanism 3, bridge mechanism 2 and threshing mechanism 6, ensuring the continuity and stability of the overall operation.

[0058] like Figure 3 As shown, the bridge mechanism 2 is equipped with a chain rake conveying assembly for transporting corn crops. This assembly consists of sprockets 202, chains 204, and multiple U-shaped chain rakes 201. The sprockets 202 are respectively installed at the front and rear ends of the bridge mechanism 2, and form a power transmission mechanism through the bridge drive wheel 107, bridge transmission wheel 106, and bridge transmission shaft 205, which drives the chain rake conveying assembly to operate continuously along a set path. The chains 204 are wound around the sprockets 202 and connected to the multiple U-shaped chain rakes 201. The multiple U-shaped chain rakes 201 are evenly distributed between the chains 204, used to push the corn crops from the feeding section to the threshing mechanism 6. Bearing seats 203 are provided at both ends of the bridge transmission shaft 205.

[0059] like Figure 4As shown, the feeding mechanism 3 includes a first feeding roller and a second feeding roller. The first feeding roller is equipped with a toothed rack 301, a toothed screen 302, a pulley 104, a drive shaft 304, and an octagonal metal plate 303. The octagonal metal plate 303 is spaced and fitted onto the drive shaft 304. The toothed rack 301 is fixed to the corresponding position of the octagonal metal plate 303 by bolts, forming a first feeding roller with feeding function. The toothed screen 302 is installed on the machine housing 5, located below the first feeding roller, and cooperates with the first feeding roller to form a crop feeding channel, but the two do not directly contact each other.

[0060] like Figure 5 As shown, the second feed roller includes a straight feed plate 306, a spiral feed plate 307, a second feed roller shaft 308, and a second feed roller drive shaft 309. One end of the second feed roller shaft 308 is fixedly connected to the second feed roller drive shaft 309, which is driven to rotate by the second feed roller pulley 103, thereby driving the entire second feed roller to rotate synchronously. Multiple straight feed plates 306 are evenly distributed along the axial direction of the second feed roller shaft 308, and are flat strips in shape, used for shaping and uniformly advancing the crop. The spiral feed plate 307 is spirally wound on the outer surface of the second feed roller shaft 308. During the rotation of the second feed roller, it works in conjunction with the straight feed plates 306 to guide the crop from the direction of the first feed roller into the subsequent threshing mechanism 6, and improves the continuity and uniformity of the axial movement of the material.

[0061] like Figure 6 As shown, the threshing mechanism 6 includes a longitudinal axial flow threshing drum, which is provided with a threshing drum body 601, spiral blades 602, a feeding cone 603, threshing and kneading teeth 604, cylindrical toothed rods 605, a threshing drum shaft 606, and a threshing drum screen 607. The front end and the rear end of the threshing drum body 601 are respectively provided with the feeding cone 603 and the threshing drum shaft 606. The spiral blades 602 are provided on the feeding cone 603. The threshing and kneading teeth 604 and the cylindrical toothed rods 605 are sequentially arranged on the threshing drum body 601 along the direction from the feeding cone 603 to the threshing drum shaft 606. The threshing drum screen 607 is installed at the bottom of the threshing chamber below the threshing drum body 601.

[0062] The outer surfaces of the threshing drum body 601, the spiral blades 602, and the feeding cone 603 are all treated with HVOF sprayed tungsten carbide coating. This coating has excellent adhesion and adjustable surface roughness, significantly improving the surface hardness, wear resistance, and friction adjustment capability of the components, effectively preventing clogging, slippage, or structural damage caused by localized over-wear or surface wear. The threshing and kneading teeth 604 are made of thermosetting polyurethane material, which has good elastic modulus, wear resistance, and wet working stability. It can reduce damage to the kernels while ensuring threshing force, making it particularly suitable for corn harvesting operations with a wide range of moisture content. The cylindrical toothed rod 605 is made of high-strength alloy steel, with extremely high surface hardness and impact resistance. It is specifically used for supplementary threshing and final removal of stubborn kernels remaining in the later stages of threshing, ensuring thorough threshing.

[0063] The monitoring device 4 includes an ambient humidity sensor and a pressure sensor. The ambient humidity sensor is installed at the front end of the bridge mechanism 2 to monitor the relative humidity of the working environment in real time, serving as an indirect assessment of crop moisture content and determining the difficulty of threshing. The pressure sensors include a first pressure sensor located between the bridge mechanism 2 and the first feeding roller, and second and third pressure sensors located at the front and rear sections of the threshing mechanism 6. These sensors sense the instantaneous feed load of the crop entering the device, reflect the crop flow rate and flow status in real time, and monitor the force changes of the crop in the initial and final stages of threshing, reflecting the clogging trend and resistance distribution characteristics during the threshing process. The four sets of sensors work together to achieve full-process perception of load distribution, humidity influence, and force changes from crop feeding to threshing, providing accurate decision-making basis for the control system.

[0064] As the core of intelligent control of the whole machine, the control system performs real-time calculation and risk assessment on the monitoring data based on the PLC controller and simulation database.

[0065] R = α × (P) f -P r )+β×P in +γ×H;

[0066] Where R represents the congestion risk factor, P in H represents the feed pressure, P represents the ambient humidity. f P represents the pressure at the front of the threshing drum. r The pressure at the rear of the threshing drum is represented by α, β, and γ, which are all system adjustment coefficients.

[0067] Based on the congestion threshold, a speed adjustment command is generated and sent to the cab interface to adjust the engine speed.

[0068] N e =N0-k×max(0,RR)th );

[0069] Where N0 represents the engine base speed, k represents the speed adjustment sensitivity coefficient, and N e R represents the adjusted target engine speed. th This indicates the threshold for blocking risks.

[0070] This speed regulation mechanism enables intelligent response adjustment of the power system, improving adaptability and preventing stalling.

[0071] The machine casing 5 is a metal shell structure used to form a closed ring-shaped crop conveying structure, protecting the conveying system from external dust, debris, and mechanical damage, while also facilitating equipment maintenance and cleaning. The chain rake conveying components, power and transmission mechanisms 1 of the bridge mechanism 2 are all located inside the enclosed machine casing 5, ensuring that the entire conveying and threshing process takes place in a relatively closed and stable environment, improving operational safety and reliability.

[0072] It is worth noting that all contents not described in detail in this invention are existing technologies and are well known to those skilled in the art.

[0073] Therefore, the present invention adopts the above-mentioned high moisture content corn threshing mechanism based on a PLC system, which solves the problems of mismatch between driving speed and field crop characteristics, inaccurate adjustment of threshing parameters, high threshing loss rate, high fuel consumption and easy blockage in the operation of traditional corn combine harvesters.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A high-moisture-content corn threshing mechanism based on a PLC system, characterized in that, include: The power and transmission mechanism includes an engine, an engine output wheel, and a multi-stage pulley. The multi-stage pulley consists of a threshing drum drive pulley, a second feed roller pulley, a first feed roller pulley, a tensioning wheel, a bridge drive wheel, and a bridge drive wheel. The engine is connected to the multi-stage pulley through the engine output wheel, and the operating speed of the feeding mechanism, the bridge mechanism, and the threshing mechanism is synchronously controlled by dynamically adjusting the engine speed. In the power and transmission mechanism, the engine output wheel has a three-stage fixed diameter combination structure, namely 140mm, 180mm, and 220mm; When the crop moisture content is greater than or equal to 20% and less than 25%, the engine output wheel should be a combination type with a diameter of 140mm. When the crop moisture content is greater than or equal to 25% and less than 30%, the engine output wheel should be a combination type with a diameter of 180mm. When the crop moisture content reaches 30% or more, the engine output wheel should be a combination type with a diameter of 220mm. The bridging mechanism includes a chain rake conveyor assembly, which consists of a sprocket, a chain, and multiple U-shaped chain rakes, and is used to convey corn crops from the feeding section to the threshing mechanism. The feeding mechanism includes a first feeding roller and a second feeding roller. The first feeding roller is provided with a textured rack, a textured screen, a first feeding roller drive shaft, and an octagonal metal plate. The second feeding roller is provided with a straight feeding plate, a spiral feeding plate, a second feeding roller shaft, and a second feeding roller drive shaft. The spiral feeding plate is spirally wound on the outer surface of the second feeding roller shaft and located at both ends of the straight feeding plate. The threshing mechanism includes a longitudinal axial flow threshing drum, which is provided with a threshing drum body, spiral blades, a feeding cone, threshing and kneading teeth, cylindrical toothed rods, a threshing drum shaft, and a threshing drum screen; an angle adjustment mechanism is provided between the threshing drum body and its support base, which is controlled by a PLC control system and its tilt angle adjustment range is 15°~20°. The control system consists of a monitoring system, a controller, and an execution system. The monitoring system collects operating parameters of the threshing section and the conveying path in real time. The monitoring system includes an environmental humidity sensor installed at the front end of the bridge mechanism to monitor the relative humidity of the working environment in real time, serving as an indirect assessment of crop moisture content. The controller, based on a PLC platform, processes and analyzes the collected data and calculates blockage risk factors. The execution system dynamically adjusts the engine speed and locomotive speed according to the instructions output by the controller. The formula for calculating the congestion risk factor is as follows: ； in, Indicates the risk factor of blockage. Indicates the feed pressure. Indicates ambient humidity. This indicates the pressure at the front of the threshing drum. This indicates the pressure at the rear of the threshing drum. , , Both represent system adjustment coefficients; Based on the congestion threshold, a speed adjustment command is generated and sent to the cab interface to adjust the engine speed. ； in, Indicates the engine's base speed. This indicates the speed adjustment sensitivity coefficient. This indicates the target engine speed after adjustment. This indicates the threshold for blocking risks.

2. The high-moisture-content corn threshing mechanism based on a PLC system according to claim 1, characterized in that, The chain rake conveying assembly, power and transmission mechanism of the bridge crossing mechanism are located inside the machine housing, which is a metal shell structure. The sprockets are installed at both ends of the bridge mechanism and are connected to the bridge drive wheel and bridge transmission wheel through the bridge drive shaft. The chain is installed on the sprocket, and multiple U-shaped chain rakes are fixed at equal intervals between the chain to form a closed-loop conveying structure. Bearing seats are provided between the bridge drive wheel and the adjacent sprocket, and between the bridge drive wheel and the connected sprocket.

3. The high-moisture-content corn threshing mechanism based on a PLC system according to claim 1, characterized in that, Octagonal metal plates are spaced and fitted onto the drive shaft of the first feed roller. A toothed rack is fixed to the corresponding position of the octagonal metal plate by bolts. A toothed screen is installed on the machine housing, located below the first feed roller, and cooperates with the first feed roller to form a crop feeding channel. A slide rail is provided between the toothed screen and the first feed roller.

4. The high-moisture-content corn threshing mechanism based on a PLC system according to claim 3, characterized in that, One end of the first feed roller drive shaft is fixedly connected to the first feed roller driven wheel, and the first feed roller driven wheel drives the feed roller drive shaft to rotate.

5. A high-moisture-content corn threshing mechanism based on a PLC system according to claim 4, characterized in that, The second feed roller drive wheel is fixedly connected to the outside of the second feed roller shaft, and the straight feed plates are evenly arranged along the axial direction of the second feed roller shaft.

6. The high-moisture-content corn threshing mechanism based on a PLC system according to claim 1, characterized in that, The front and rear ends of the threshing drum body are respectively provided with a feeding cone and a threshing drum shaft. The feeding cone is provided with spiral blades. Along the direction from the feeding cone to the threshing drum shaft, threshing kneading teeth and cylindrical toothed rods are sequentially provided on the threshing drum body. A threshing drum screen is installed at the bottom of the threshing chamber below the threshing drum body.

7. A high-moisture-content corn threshing mechanism based on a PLC system according to claim 6, characterized in that, The outer surfaces of the threshing drum body, spiral blades, and feeding cone of the longitudinal axial flow threshing drum are all treated with HVOF sprayed tungsten carbide coating.

8. A high-moisture-content corn threshing mechanism based on a PLC system according to claim 1, characterized in that, The monitoring system also includes pressure sensors, including: a first pressure sensor disposed between the bridge mechanism and the first feed roller, and a second and a third pressure sensor disposed in the front and rear sections of the threshing mechanism. The monitoring device collects various signals and transmits them to the PLC controller in real time to determine the current operating status and generate control commands to send to the execution system, thereby adjusting the engine power output and vehicle speed.

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