The direct sowing of rapeseed requires shallow tillage for stubble removal, which can cause significant vibrations that impact the seed metering device, thereby affecting the quality of seeding. This study focuses on a double-row hole-wheel-type seed metering device on the 2BYG-220 type combined rapeseed planter. Initially, vibrations experienced by the seed drill during field operations were measured and analyzed, revealing that the vibration frequencies during field operations predominantly ranged between 0 and 25 Hz. Consequently, an eccentric wheel–return-spring-type vibration seed metering test rig was designed, manufactured, and set up. By swapping out the eccentric wheel on the test rig, the amplitude was mainly concentrated within 3 mm. The test results indicate that amplitude had a minimal impact on the performance of the double-row hole-wheel-type rapeseed seed metering device, whereas vibration frequency had a more significant effect. When the vibration frequency was between 0 and 10 Hz, the seed metering device maintained a stable output between 7.6 and 8.2 g/min, with minimal impact from vibrations: the coefficient of variation for seeding uniformity ranged between 35.81% and 44.58%, indicating stability and good uniformity. However, when the vibration frequency ranged from 10 to 24 Hz, the output of the seed metering device decreased rapidly and exhibited a linear relationship with frequency changes, with a determination coefficient (R²) of 0.92376. The coefficient of variation for seeding uniformity increased rapidly and also showed a linear relationship with frequency changes, with a determination coefficient (R²) of 0.87973. Vibrations with frequencies greater than 10 Hz had a considerable impact on the performance of the seed metering device.

Objective: This study was conducted to address the harsh working environment of agricultural machinery and improve the wear resistance of soil-contacting components such as rotary tiller blades, thereby extending their service life. Method: Plasma-cladding technology was employed to prepare an iron-based wear-resistant coating on the surface of rotary tiller blades. The following parameter combination was optimized using response surface methodology (RSM): a cladding current of 144A, a cladding speed of 23 mm/s, a powder feeding rate of 23 g/min, and a cladding distance of 12 mm. The microstructure morphology, phase composition, microhardness, and wear resistance of the wear-resistant cladding layer were investigated. Results: The results indicate that the interface of the cladding layer is clean and free from significant porosity or defects, exhibiting good metallurgical bonding with the substrate. The primary phases identified in the cladding layer include α-Fe, Cr₇C₃, Cr₂Fe₁₄C, and Cr-Ni-Fe-C solid solutions. The average hardness of the cladding layer is 1171 Hv0.5, approximately 2.9 times that of the substrate. In wet sand–rubber wheel wear tests under identical conditions, the weight loss of the cladding layer is only 1/21 that of 65Mn steel, with minimal wear morphology. Field trials showed that the wear of the cladding layer rotary tiller blade was reduced by 24.5% compared with the unclad blade. The presence of the cladding layer significantly protected the integrity of the cutting edge, ensuring the functionality of the rotary tiller blade in cutting and throwing soil; thus, its original appearance was maintained even after prolonged wear. The findings of this study can provide a valuable reference for the enhancement of wear resistance for other soil-contacting components.

吴志立 1, 2 , 李玉阁 1 , 吴 彼 1 , 雷明凯 1 (1. 大连理工大学 材料科学与工程学院 表面工程实验室, 大连 116024; 2. 湖南农业大学 工学院, 南方粮油作物 协同创新中心, 长沙 410128) 摘 要: 采用高功率调制脉冲磁控溅射 Al/(Al+Ti)原子比(x)分别为 0.25、 0.5 和 0.67 的 TiAlSi 合金靶, 溅射功率 1~4 kW, 氮气分压 25%, 工作气压 0.3 Pa, 在 Si(100)和 AISI 304 奥氏体不锈钢基片上沉积了 TiAlSiN 纳米复合涂层。 TiAlSiN 涂层中氮含量保持在 52.0at%~56.7at%之间, 均形成了 nc-TiAlN/a-Si 3 N 4 /AlN 纳米晶/非晶复合结构。随着原子比 x 增加, 非晶含量增加, 涂层硬度先升高而后降低。当 x=0.5 时, 硬度最高可达 28.7 GPa。溅射功率升高可提高溅射 等离子体中金属离化程度, 促进涂层调幅分解的进行, 形成了界面清晰的非晶包裹纳米晶结构, 且晶粒尺寸基本 保持不变。当 x=0.67 时, 溅射功率由 1 kW 上升到 4 kW 时, 硬度由 16.4 GPa 升至 21.3 GPa。不同靶材成分和溅射功 率条件下沉积的 TiAlSiN 涂层的磨损率为(0.13~6.25)×10-5 mm 3 /(N•m), 具有优良的耐磨性能。当 x=0.67, 溅射功率 2 kW 时, nc-TiAlN/a-Si 3 N 4 纳米复合涂层具有最优的耐磨性能。

This study involves the design of an integrated machine dedicated to the core processes of classifying, shelling, and cleaning to address the critical drawbacks of existing Camellia oleifera fruit processing equipment, including the high manual labor requirement, low operating efficiency, unsatisfactory shelling and cleaning performance, and severe camellia seed damage. The classifying system employed a slat drum structure, and response surface methodology (RSM) was utilized to determine and optimize its operating parameters: spiral blade speed: 20 rpm; drum speed: 10 rpm; and rise angle: 9.6°. The shelling system employed a horizontal flexible structure, and polyurethane was the core material. We determined through single-factor experiments that the shelling drum rotation speed was 200 rpm. For the cleaning system, a composite mode integrating drum screening and friction separation was adopted, and single-factor experiments further determined the optimal operating parameters: cleaning drum rotation speed: 20 rpm; friction conveyor shaft rotation speed: 150 rpm; and cleaning inclination angle: 25°. The performance test verified that the integrated machine achieved outstanding results: the shelling rate reached 97.52%, the camellia seed breakage rate did not exceed 2.42%, the impurity content rate did not exceed 1.99%, the loss rate was less than 3.66%, and the processing capacity reached 2614 kg/h.

To address the low shelling rate and high seed breakage in existing oil tea fruit shelling devices, a novel laser scoring device was designed for fresh Camellia oleifera fruits. Experimental studies were conducted to optimize the key parameters of the custom-built laser scoring machine, aiming to improve scoring qualification rates. Through single-factor tests and response surface methodology, a regression model was developed to characterize the relationship between the scoring qualification rate and the following three variables: conveyor speed (12 mm/s), laser power (97 W), and defocusing distance (10 mm). The study revealed interactive effects among these parameters. After optimization and verification under ideal conditions, the device achieved a peak average qualification rate of 85.6%.

Against the background of severe wear failure of Rotary Tillage blades restricting agricultural tillage efficiency, this study aimed to explore wear resistance differences, reveal wear mechanisms and locate critical failure zones to support blade material selection, structural optimization and localized strengthening. Five commercial IT195 Rotary Tillage blades made of 65Mn and 60Si2Mn steels were tested via a soil-bin rotary wear test rig. Microstructure, hardness and wear morphology were characterized by metallographic microscopy, Vickers hardness test and SEM, while 3D scanning and stress simulation were adopted to analyze full-cycle wear behavior of the optimal blade. The results showed that the E-type blade with 60Si2Mn possessed the best wear resistance, with minimum mass and dimensional wear loss and the gentlest wear rate, attributed to its single-phase acicular martensite and high hardness of 627.73 HV, forming uniform shallow grooves and suppressing micro-cutting and spalling. Full-cycle wear analysis demonstrated highly uneven wear distribution, with the bend transition zone linking tangential and side cutting regions identified as the critical failure zone featuring the largest wear depth and fastest material loss, verified by stress concentration from simulation. This work provides theoretical support and targeted references for material optimization, structural design and surface strengthening of key regions of Rotary Tillage blades.