Search

At this stage, the domestic development of apple tree seedling planting machines is still in its infancy, and few planting machines had been developed for apple trees. Planting apple trees requires a large amount of labor, but the current shortage of labor is a prominent contradiction. The problem of non-mechanized planting of apple tree seedlings urgently needs to be solved. In order to solve the problems in the apple planting process under the current high density dwarfing orchard cultivation mode: low manual planting efficiency, unsatisfactory erection of fruit seedlings with the developed machines, and slightly higher coefficient of variation of plant spacing caused by the slippage of the clamping belt. Under the guidance of agricultural machinery and agronomic integration technology, a two-point clamping apple seedling planting machine was developed by a combination of extensive research, virtual design, prototype manufacturing, and field trials. This machine is based on the existing continuous ditching fixed-distance planting machine previously developed by the same team, and implements structural improvements and performance optimization. Firstly, the fruit seedling clamping device is improved, and the fruit seedlings are clamped at the upper and lower points. On top of the previous generation planting machine, a layer of clamping and conveying device is installed above the lower clamping and conveying device, and the upper and lower layers are perpendicular to each other. The distance is set to be 50cm, which is based on the comprehensive consideration of the height and status of the apple tree seedlings and the comparison of the planting effectiveness at different distances. The upper and lower clamping points work with each other during the transportation of apple tree seedlings to clamp the apple tree seedlings together. The apple tree seedlings will not rotate during operation and maintain a good initial status. It overcomes the problem that it is difficult to guarantee the initial angle of the tall seedlings relative to the ground because of the original one-point clamping, and significantly improves the perpendicularity after planting; Secondly, the transportation method is improved and the coefficient of variation of plant spacing is reduced. Considering that the trunk and bark of apple tree seedlings should not be damaged during the clamping and conveying process of the transplanter, the solution was still sought in the belt category. The initial idea was to add more tension wheels to change the belt slippage. However, the experimental results observed showed that this method makes almost no effect on reducing the belt slip rate. The timing belt can ensure that the apple tree seedlings are protected from damage during the clamping and conveying process, and it has a good transmission effect with little sliding. In order to improve clamping, the conveying mode adopts two synchronous belts to clamp and convey apple seedlings, which has a lower slip rate than the original V-belt clamping and conveying, and significantly reduces the coefficient of variation of the plant spacing; in addition, the power matching is optimized by the corresponding calculation formula. The depth-limiting wheel is installed to improve the stability of the planting depth, and the ditching machine, plant spacing control and other parts follow the first-generation machine plan. According to the planting requirements of different varieties of seedlings, the depth and width of the ditch can be adjusted, and the planting distance can also be adjusted as needed, and the adjustment is simple and convenient. Field tests showed that the qualified rate of apple seedlings planted by the machine is increased from 90.63% to 97.14%, the average planting depth qualified rate is increased from 91.43% to 93.33%, and the average plant spacing coefficient of variation is reduced from 5.03% to 3.74%, and the planting efficiency is increased from 11.89 plants/min to 12.26 plants/min, which was 37 times faster than that of manual planting. Compared with the existing machines, all performances have been improved, laying a solid foundation for the subsequent mechanization of apple's production. [ABSTRACT FROM AUTHOR]

Aiming at the present situation of high labor intensity and low precision of plant spacing control in fruit tree planting, the agricultural machinery agronomic integration technology based on standardized cultivation mode was studied in this paper, and an apple planting machine for high density dwarfing orchard was designed, the key technical problems in mechanized planting of fruit seedlings, such as continuous wide and deep furrow opening, vertical planting of fruit seedlings and precise control of plant spacing, were solved. The apple planting machine for high density dwarfing orchard was powered by a tractor above 58 kW and used a rear three-point suspension operation mode. The structure mainly composed of continuous ditching device, clamping and conveying device, fixed-distance planting device, overburden pressing device and other auxiliary devices. The ditching device was powered by power-output shaft to drive opener ditching continuously. V-type double-disc opener was used, ditching blade was installed on ditch cutter supported by inclined bearings. Soil retaining plate was installed at the rear of the opener, front and side plates were used with the opener to ensure the grooving structure was stable. Bottom plate was used together with grid bar to assist positioning. By manually placing the seedlings and placing the rotes on the bottom plate, the tree trunk was placed obliquely on the grid bar lying on the conveying channel for initial positioning. After the sensor of the fixed-distance planting device installed at the rear of the frame detected the position information of the planted seedlings, the cylinder action of the clamping conveyor was started by controlling the switch. the positioning bar was opened, and the seedlings entered the clamping state, and then the seedlings were transmitted backward by the carrying belt. The carrying belt was powered by the ground wheel with the same rate, therefore, the speed of the carrying belt was the same as the machine working speed, and the seedlings were placed in the planting ditch statically with a zero speed relative to the ground, then the scraper-type cover pushed back the soil and the compaction wheel pressed the soil compactly, at the same time it pushed forward the seedlings to complete the upright planting. The fixed-distance sensor detected the seedlings just planted, the process was repeated, ensuring the distance between the adjacent 2 seedlings was equal, continuous ditching, vertical planting, backfilling and repressing were realized in one-time. By adjusting the height of the bottom plate (from 0 to 20 cm), the angle and depth for initial inclined positioning could be changed, so that the machine could work in different soils and for different varieties. The ditching depth of the machine was adjustable from 0 to 40 cm, the ditching width was 30~37 cm, and the working speed was 0.8-1.5 km/h. The results of field experiment showed that the average qualification rate for planting depth was 91.43%, the average planting qualification rate was 93.79%, and the variation coefficient of plant spacing was about 5.03%, average planting efficiency was about 720 plants per hour, which was 36 times more efficient than manual planting, the machine worked stably and the planting effect met the mechanized production requirements of modern standard orchard. [ABSTRACT FROM AUTHOR]