Parameter optimization method for rotary cultivator with low-speed small-bending-angle rotary blade

Abstract

The invention provides a parameter optimization method for a rotary cultivator with a low-speed small-bending-angle rotary blade, belongs to the field of agricultural mechanical equipment, and analyzes, researches and optimizes the bending angle of the existing rotary blade, the edge angle of the rotary blade and the rotating speed of a rotating body. The bending angle alpha of the rotary blade, the cutting edge angle beta of the rotary blade and the rotating speed n of the rotating body are used as test factors, the soil crushing rate M and the torque T are used as evaluation indexes, three-factor and three-horizontal orthogonal tests are carried out on the machine tool, and after range and variance analysis is carried out on the test results, the obtained better structure parameter combination is as follows: the bending angle alpha of the rotary blade is equal to 132 degrees, and the bending angle beta of the rotary blade is equal to 132 degrees; the edge angle beta of the rotary blade is 20 degrees, and the rotating speed n of the rotary body is 150 r / min; according to actual production requirements, the better structure parameter combination is adjusted as follows: the bending angle alpha of the rotary blade is equal to 132 + / -5 degrees, the cutting edge angle beta of the rotary blade is equal to 20 + / -2 degrees, and the rotating speed n of the rotary body is equal to 150 + / -10 r / min; the rotary cultivator used by the optimization method comprises a rack, a rotary body and a transmission assembly. The parameter optimization method is novel, the structural parameter combination is reasonable, the soil crushing rate is high, and the machine load is small.

Description

Technical Field

[0001] This invention provides a method for optimizing the parameters of a low-speed rotary tiller with small bending angle blades, belonging to the field of agricultural mechanization equipment. Rotary tillers manufactured according to the optimized parameters are mainly used for tillage operations before sowing various crops. Background Technology

[0002] China is a major agricultural producer. While the extensive use of various agricultural machinery has improved crop yields and quality, the compaction of soil by the tires or tracks of these machines, coupled with years of plowing at the same depth, creates a relatively solid plow pan. This severely hinders the downward growth of crop roots, preventing them from absorbing water and nutrients, thus leading to a decrease in crop yields. Currently, there are various types of tillage machinery available, but rotary tillers are the most commonly used. Rotary tillage creates a broken soil layer, increases soil porosity, and minimizes nutrient loss, thereby improving soil quality and increasing crop yields.

[0003] Soil breakage rate is a crucial evaluation indicator for rotary tillers, generally requiring a breakage rate of ≥60%. In actual production, a higher breakage rate means a higher rotational speed and sharper blades are needed for the rotating body composed of the rotary blades and shaft. Tests on existing rotary tillers have shown an average breakage rate of 61.25% and an average torque as high as 785.13 N·m. This also means the rotary tiller must withstand a greater load, significantly increasing energy consumption and making it more prone to damage. Conversely, if the breakage rate is insufficient, it will affect the soil loosening effect, leading to lower-than-expected crop yields. Therefore, extensive research and improvements have been made to rotary tillers, but a balance between effective soil breakage and reduced load and energy consumption remains elusive. Balancing the relationship between the rotary tiller's load and breakage rate has become a key focus and challenge in the design process.

[0004] Looking at the current state of the agricultural mechanization equipment industry, there is an urgent need for a parameter optimization method for low-speed, small-bend-angle rotary tillers with reasonable structural parameters, high soil breaking rate, low implement load, low energy consumption, and high operational reliability. Summary of the Invention

[0005] The purpose of this invention is to provide a parameter optimization method for low-speed, small-bend-angle rotary tillers that can overcome the problems existing in the current agricultural mechanization equipment industry. This method features novel parameter optimization methods, reasonable structural parameter combinations, high soil breaking rate, low implement load, and high operational reliability.

[0006] The technical solution is as follows: The bending angle, cutting edge angle, and rotational speed of existing rotary tillers were analyzed, studied, and optimized. The bending angle of the rotary tiller was used as a starting point. α The cutting edge angle of rotary tillers β and rotational speedn For experimental factors, soil crushing rate M and torque T To evaluate the performance indicators, a three-factor, three-level orthogonal experiment was conducted on the machine. After range and variance analyses of the experimental results, the optimal combination of structural parameters was obtained: the bending angle of the rotary tiller blades. α =132°, the cutting edge angle of a rotary tiller. β =20°, rotational speed of the rotating body n =150r / min; Based on actual production needs, the optimal combination of structural parameters was adjusted to: the bending angle of the rotary tiller blades. α =132±5°, the cutting edge angle of the rotary tiller. β =20±2°, rotational speed of the rotating body n =150±10r / min.

[0007] The parameter optimization method for low-speed, small-bend-angle rotary tillers described above optimizes the rotary tiller, which includes a frame, a rotating body, and a transmission assembly, according to the optimal combination of structural parameters.

[0008] The rotary tiller optimized according to the parameter optimization method for low-speed, small-bend-angle rotary tillers, with the best combination of structural parameters, has a frame including crossbeams, end plates, depth limiting plates, suspension frames, guards, protective plates, and elastic components. Two crossbeams are fixedly connected at both ends by an end plate. The two crossbeams are parallel to each other, and the surfaces of the two end plates are parallel to each other and perpendicular to the crossbeams. An arc-shaped depth limiting plate is installed on the same edge of each end plate relative to the plane of the two crossbeams. The gantry-shaped suspension frame is installed on... In the middle of the crossbeam, the gantry plane of the suspension frame is parallel to the crossbeam, and the gantry of the suspension frame extends outward in the direction away from the depth limit plate; a protective cover is installed on the side of the two crossbeams away from the depth limit plate, the protective cover is hinged to the crossbeam without the suspension frame installed, and the two ends of the protective cover are fastened to the outer edge of the two depth limit plates along the length of the crossbeam; two elastic components are installed above the protective cover and press the protective cover tightly against the outer edge of the two depth limit plates; the frame is suspended behind the tractor by the suspension frame, the protective cover is located on the side away from the tractor, and the two depth limit plates face downward.

[0009] The rotary tiller optimized according to the parameter optimization method for low-speed, small-bending-angle rotary tillers, with its optimal structural parameter combination, comprises rotary blades and a blade shaft. The blades, which are plate-shaped, are composed of a flat mounting section and a curved soil-breaking section. The curved soil-breaking section bends at an angle relative to the flat mounting section. α And (π / 2) < α < π; The chamfered edge of one side of the curved soil-breaking section of the rotary tiller blade forms a soil-breaking blade, and the cutting edge angle between the chamfered surface and the other side of the blade is π. β And 0 < β<(π / 2); Multiple rotary tillers are installed in pairs, symmetrically and evenly along the entire length of the tiller shaft. The curved soil-breaking sections of the rotary tillers are all bent towards both ends of the tiller shaft along the length of the shaft, and the soil-breaking blades of the rotary tillers are all facing the same circumferential direction of the shaft. The two ends of the rotary body's tiller shaft are supported on two end plates of the frame and located below the frame's crossbeam. When the rotary tillers of the rotary body rotate to the crossbeam near the side of the frame with the suspension bracket, the soil-breaking blades of the rotary tillers face downwards.

[0010] The rotary tiller optimized according to the parameter optimization method of low-speed small-bend-angle rotary tiller has a transmission component including a gearbox, an end drive, a cross shaft, and a drive shaft. The gearbox is installed above the middle of the crossbeam of the frame without the suspension bracket. The end drive is installed on the outer side of one end plate of the frame, and the power output hole of the end drive is fitted onto the protruding end of the cutter shaft of the rotating body after passing through the end plate. The two ends of the cross shaft are connected to the power output hole of the gearbox and the power input hole of the end drive, respectively. One end of the drive shaft is connected to the input shaft of the gearbox, and the other end is connected to the power output shaft of the tractor.

[0011] Compared with the existing state of the art, this invention utilizes an optimized and improved rotary tillage blade bending angle. α Rotary tillage blade corner β and rotational speed n A three-factor, three-level orthogonal experiment was conducted on the rotary tiller as an experimental factor, and range and variance analyses were performed on the experimental results to obtain the optimal parameter combination: rotary tiller blade bending angle. α =132±5°, cutting edge angle β =20±2°, rotational speed of the rotating body n=150±10r / min; Verification tests were conducted using the optimal parameter combination, achieving a soil breaking rate of 68.28% and a torque of 535.80 N·m. These represent an increase of 11.48% in soil breaking rate and a decrease of 31.76% in torque compared to existing rotary tillers. This completely solves the problem of simultaneously achieving both soil breaking effect and implement load in existing rotary tillage operations, providing a solid foundation for further research, analysis, and implement optimization. Because the optimized rotary tiller's blades face downwards on the tractor side and, driven by the transmission components, break up compacted soil into larger clods, the rotary tillers can... Large clods of soil are lifted and thrown onto the guard above and the rear guard plate of the rotary tiller for secondary crushing. Because the guard above the frame is equipped with two elastic components that can press the guard plate against the outer edge of two depth limiting plates, when the impact force of a large and hard clod of soil on the rear guard plate exceeds the preload of the two elastic components, the guard plate will compress the two elastic components and swing backward, thereby reducing the damage caused by the impact of the soil clods to the machine, thus extending the machine's service life. As the crushed small and medium-sized soil clods fall, the rotary tiller blades will further crush them, resulting in a high soil crushing rate, low energy consumption, and high operational reliability for the optimized rotary tiller. Attached Figure Description

[0012] Figure 1 This is an isometric view of an embodiment of the present invention; Figure 2 This is the present invention. Figure 1 Axonometric view of the frame in the illustrated embodiment; Figure 3 This is the present invention. Figure 1 Axonometric view of the rotating body in the embodiment shown; Figure 4 This is the present invention. Figure 3 The diagram shows the bending angle of the rotary tiller blades in the embodiment and their contact with the soil during operation; Figure 5 This is the present invention. Figure 3 A cross-sectional view of the rotary tiller blades in the illustrated embodiment; Figure 6 This is the present invention. Figure 1 The isometric view of the transmission assembly in the illustrated embodiment.

[0013] Among them, 1. Frame; 11. Crossbeam; 12. End plate; 13. Depth limiting plate; 14. Suspension frame; 15. Protective cover; 16. Protective plate; 17. Elastic component; 2. Rotary body; 21. Rotary tiller; 22. Blade shaft; 3. Transmission component; 31. Gearbox; 32. End drive; 33. Horizontal shaft; 34. Drive shaft. Detailed Implementation

[0014] exist Figure 1 and Figures 3-5In the embodiment shown: the bending angle of the existing rotary tiller blade 21, the cutting edge angle of the rotary tiller blade 21, and the rotational speed of the rotating body 2 were analyzed, studied, and optimized, with the bending angle of the rotary tiller blade 21 as the main factor. α The cutting edge angle of rotary tiller 21 β and the rotational speed of the rotating body 2 n For experimental factors, soil crushing rate M and torque T To evaluate the performance indicators, a three-factor, three-level orthogonal experiment was conducted on the machine. After range and variance analysis of the experimental results, the optimal combination of structural parameters was obtained: the bending angle of the rotary tiller blade 21. α =132°, the cutting edge angle of rotary tiller 21 β =20°, rotational speed of the rotating body 2 n =150r / min; According to actual production needs, the optimal combination of structural parameters was adjusted to: the bending angle of the rotary tiller blade 21. α =132±5°, the cutting edge angle of rotary tiller 21 β =20±2°, rotational speed of the rotating body 2 n =150±10r / min.

[0015] exist Figures 1-6 In the embodiment shown: the two crossbeams 11 of the rotary tiller frame 1 used in the optimization method are fixedly connected at both ends by an end plate 12. The two crossbeams 11 are parallel to each other, and the surfaces of the two end plates 12 are parallel to each other and perpendicular to the crossbeams 11. Each end plate 12 is equipped with an arc-shaped depth limiting plate 13 at the same edge of the plane where the two crossbeams 11 are located, so as to limit the variation of the rotary tillage depth during the operation of the implement. A gantry-shaped suspension frame 14 is installed in the middle of one of the crossbeams 11, and the gantry plane of the suspension frame 14 is parallel to the crossbeam 11. The gantry of the suspension frame 14 extends outwards in the direction away from the depth limit plate 13; a guard 15 is installed on the side of the two crossbeams 11 away from the depth limit plate 13, and the guard plate 16 is hinged to the crossbeam 11 without the suspension frame 14 installed, and the guard plate 16 is fastened to the outer edge of the two depth limit plates 13 at both ends along the length of the crossbeam 11; two elastic components 17 are installed above the guard 15 and press the guard plate 16 tightly against the outer edge of the two depth limit plates 13; the frame 1 is suspended behind the tractor by the suspension frame 14, the guard plate 16 is located on the side away from the tractor, and the two depth limit plates 13 face downwards. The rotary tiller 21 of the rotating body 2 is a sheet-shaped rotary tiller blade composed of a flat mounting section and a curved soil breaking section, and the bending angle of the curved soil breaking section relative to the flat mounting section is... α And π / 2 < α < π; The edge of one side of the curved soil-breaking section of the rotary tiller blade 21 is chamfered to form a soil-breaking blade, and the cutting edge angle between the chamfered surface and the other side of the blade is π. β And 0 < β<π / 2; Multiple rotary tillers 21 are installed in pairs, symmetrically and evenly along the entire length of the blade shaft 22, so that the soil is broken up evenly across the entire working width; The curved soil-breaking sections of the rotary tillers 21 are all bent towards both ends of the blade shaft 22 along the length of the blade shaft 22, and the soil-breaking blades of the rotary tillers 21 are all facing the same circumferential direction of the blade shaft 22, so as to perform unidirectional cutting on compacted soil; The two ends of the blade shaft 22 of the rotating body 2 are respectively supported on the two end plates 12 of the frame 1 and located below the crossbeam 11 of the frame 1. When the rotary tillers 21 of the rotating body 2 rotates to the crossbeam 11 near the side of the frame 1 where the suspension frame 14 is installed, the soil-breaking blades of the rotary tillers 21 face downwards. The gearbox 31 of the transmission assembly 3 is installed above the middle of the crossbeam 11 of the frame 1 without the suspension bracket 14. The end drive 32 is installed on the outer side of an end plate 12 of the frame 1, and the power output hole of the end drive 32 is fitted onto the protruding end of the cutter shaft 22 of the rotary body 2 after passing through the end plate 12. The two ends of the horizontal shaft 33 are connected to the power output hole of the gearbox 31 and the power input hole of the end drive 32, respectively. One end of the drive shaft 34 is connected to the input shaft of the gearbox 31, and the other end is connected to the power output shaft of the tractor. Thus, the output power of the tractor can be transmitted to the gearbox 31. After the gearbox 31 changes speed, the rotary body 2 is driven to rotate through the horizontal shaft 33 and the end drive 32. When the rotary blade 21 of the rotary body 2 rotates to the crossbeam 11 near the side of the frame 1 with the suspension bracket 14, the linear velocity direction of the rotary blade 21 points to the ground. During operation, the rotary tiller blades 21 cut the compacted soil into larger clods. These clods are then lifted and thrown onto the protective cover 15 above the tiller and the rear guard plate 16 for secondary crushing. When the impact force of a large, hard clod on the rear guard plate 16 exceeds the preload of the two elastic components 17 on the frame 1, the guard plate 16 will compress the two elastic components 17 and swing backward, thus reducing the damage caused by the impact of the soil clods. When the impact force of the soil clods on the guard plate 16 is less than the preload of the two elastic components 17, the guard plate 16 will swing back under the elastic action of the two elastic components 17 and press against the outer edge of the two depth limiting plates 13 again. As the crushed small and medium-sized clods fall, the rotary tiller blades 21 further crush them. Therefore, the optimized rotary tiller has a high soil crushing rate, low energy consumption, and high operational reliability.

[0016] The working principle of the rotary tiller manufactured according to the optimized parameters is as follows: After being suspended behind the tractor and with the end of the drive shaft connected to the tractor's power output shaft, the rotary tiller aligns with the direction and position of the field to be tilled and performs rotary tillage.

[0017] During operation, the rotary tiller blades, positioned closer to the tractor, face downwards and, driven by the transmission assembly, break up the compacted soil into larger clods. These larger clods are then lifted and thrown against the overhead guard and rear guard plate for secondary crushing. When the impact force of a large, hard clod on the rear guard plate exceeds the preload of the two elastic components of the frame, the guard plate compresses these components and swings backwards, reducing damage from the impact. When the impact force is less than the preload of the elastic components, the guard plate swings back under their elasticity and presses against the outer edge of the two depth-limiting plates. As the crushed smaller clods fall, the rotary tiller blades further refine them.

Claims

1. A method for optimizing parameters of a low-speed, small-bend-angle rotary tiller, characterized by: The bending angle, cutting edge angle, and rotational speed of the rotary tiller (21) were analyzed and optimized. The bending angle of the rotary tiller (21) was used as the basis for the optimization. α The cutting edge angle of the rotary tiller (21) β Rotational speed of the rotating body (2) n For experimental factors, soil crushing rate M and torque T To evaluate the performance indicators, a three-factor, three-level orthogonal experiment was conducted on the machine. After range and variance analysis of the experimental results, the optimal combination of structural parameters was obtained: the bending angle of the rotary tiller blade (21). α =132°, the cutting edge angle of the rotary tiller (21) β =20°, Rotational speed of the rotating body (2) n =150r / min; According to actual production needs, the optimal combination of structural parameters is adjusted to: the bending angle of the rotary tiller (21) α =132±5°, the cutting edge angle of the rotary tiller (21) β =20±2°, Rotational speed of the rotating body (2) n =150±10r / min.

2. The parameter optimization method for a low-speed, small-bend-angle rotary tiller as described in claim 1, characterized in that: The rotary tiller optimized according to the best combination of structural parameters includes a frame (1), a rotating body (2), and a transmission assembly (3).

3. The rotary tiller optimized by the optimal combination of structural parameters obtained according to the parameter optimization method for low-speed, small-bend-angle rotary tillers as described in claim 2, characterized in that: The frame (1) includes a crossbeam (11), end plates (12), depth limiting plates (13), a suspension frame (14), a protective cover (15), a protective plate (16), and an elastic component (17). The two crossbeams (11) are fixedly connected at both ends by an end plate (12). The two crossbeams (11) are parallel to each other. The surfaces of the two end plates (12) are parallel to each other and perpendicular to the crossbeams (11). Each end plate (12) has an arc-shaped depth limiting plate (13) installed on the same side edge of the plane where the two crossbeams (11) are located. A gantry-shaped suspension frame (14) is installed in the middle of one of the crossbeams (11). The gantry plane of the suspension frame (14) is perpendicular to the crossbeam (11). The parallel, and the gantry of the suspension frame (14) extends outward in the direction away from the depth limit plate (13); the side of the two crossbeams (11) away from the depth limit plate (13) is equipped with a cover (15), the cover (16) is hinged on the crossbeam (11) without the suspension frame (14) installed, and the cover (16) is fastened to the outer edge of the two depth limit plates (13) at both ends along the length direction of the crossbeam (11), and two elastic components (17) are installed above the cover (15) and press the cover (16) against the outer edge of the two depth limit plates (13); the frame (1) is suspended behind the tractor by the suspension frame (14), the cover (16) is located on the side away from the tractor, and the two depth limit plates (13) face downward.

4. The rotary tiller optimized by the optimal combination of structural parameters obtained according to the parameter optimization method for low-speed, small-bend-angle rotary tillers as described in claim 2, characterized in that: The rotating body (2) includes a rotary tiller blade (21) and a blade shaft (22). The blade (21), which is in the form of a sheet, is composed of a flat mounting section and a curved soil-breaking section. The curved soil-breaking section is bent at an angle relative to the flat mounting section. α And (π / 2) < α < π; The edge of one side of the curved soil-breaking section of the rotary tiller (21) is chamfered to form a soil-breaking blade, and the cutting edge angle between the chamfered surface and the other side of the plate is π. β And 0 < β <(π / 2); Multiple rotary tillers (21) are installed in pairs, symmetrically and evenly along the entire length of the blade shaft (22). The curved soil-breaking sections of the rotary tillers (21) are all bent along the length of the blade shaft (22) towards both ends of the blade shaft (22), and the soil-breaking blades of the rotary tillers (21) are all facing the same circumferential direction of the blade shaft (22). The two ends of the blade shaft (22) of the rotating body (2) are respectively supported on the two end plates (12) of the frame (1) and located below the crossbeam (11) of the frame (1). When the rotary tillers (21) of the rotating body (2) rotate to the crossbeam (11) near the side of the frame (1) where the suspension frame (14) is installed, the soil-breaking blades of the rotary tillers (21) face downward.

5. The rotary tiller optimized by the optimal combination of structural parameters obtained according to the parameter optimization method for low-speed, small-bend-angle rotary tillers as described in claim 2, characterized in that: The transmission assembly (3) includes a gearbox (31), an end drive (32), a cross shaft (33), and a drive shaft (34). The gearbox (31) is installed above the middle of the cross beam (11) of the frame (1) without the suspension bracket (14). The end drive (32) is installed on the outer side of an end plate (12) of the frame (1), and the power output hole of the end drive (32) is fitted onto the protruding end of the cutter shaft (22) of the rotating body (2) after passing through the end plate (12). The two ends of the cross shaft (33) are connected to the power output hole of the gearbox (31) and the power input hole of the end drive (32) respectively. One end of the drive shaft (34) is connected to the input shaft of the gearbox (31), and the other end is connected to the power output shaft of the tractor.

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