ABSTRACT The original two-order separating sieve has a good potato-soil separating ability, but it causes significant damage to potatoes while ensuring a high potato detection rate, which in turn affects the working effectiveness of the potato digger. Thus, it is necessary to improve the design of the original swing separation sieve with a two-order sieve surface to one with a three-order sieve surface to solve the contradiction between the potato detection and potato damage. On this basis, the movement characteristics of potatoes and the separation performance of the new sieve were experimentally investigated. The experiment was conducted in a test field in Wuchuan County using a completely randomized design in a single-factor scheme with three factors and five levels, with five crank speeds (140, 150, 180, 210 and 225 rpm), five machine forward speeds (1.41, 1.51, 1.70, 1.89 and 2.21 km h-1) and five boom-connecting rod length combinations (250-350-1,030, 250-370-1,040, 270-370-1,050, 290-370-1,060 and 310-370-1,070 mm). Each experiment was repeated three times at each level, and the average value was taken as the final result. The experimental results demonstrate that the new three-order separation sieve can ensure a high potato detection rate while maintaining a low potato skin breakage rate.

RESUMO A peneira de separação de duas ordens original tem uma boa capacidade de separação batata-solo, mas causa danos significativos às batatas ao mesmo tempo em que garante uma alta taxa de evidência de batatas, o que, por sua vez, afeta a eficácia do trabalho da escavadeira de batatas. Assim, o estudo teve como objetivo aprimorar a peneira de separação de balanço original com uma superfície de peneira de duas ordens para uma nova peneira de separação com uma superfície de peneira de três ordens para resolver a contradição entre a taxa obvia de batatas e os danos às batatas na operação da peneira original. Com base nisso, as características de movimentação das batatas e o desempenho de separação da nova peneira foram investigados experimentalmente no campo. O experimento foi conduzido em um campo de teste no Condado de Wuchuan, utilizando um delineamento completamente aleatório em um esquema de fator único com três fatores e cinco níveis, com cinco velocidades de manivela (140, 150, 180, 210 e 225 rpm), cinco velocidades de avanço da máquina (1,41, 1,51, 1,70, 1,89 e 2,21 km h-1) e cinco combinações de comprimento da haste de ligação do braço (250-350-1.030, 250-370-1.040, 270-370-1.050, 290-370-1.060 e 310-370-1.070 mm). Cada experimento foi repetido três vezes em cada nível, e o valor médio foi considerado como o resultado final. Os resultados experimentais demonstram que a nova peneira de separação de três ordens pode garantir uma alta taxa de detecção de batatas enquanto mantém uma baixa taxa de danos à casca das batatas.

ABSTRACT A study was undertaken to investigate the relationship between the factors (initial height, tuber mass, tuber temperature and impact material) and the impact characteristic variables (impact velocity and bruise volume) as determined by pendulum impact test-rig. It was verified that bruise volume and maximum velocity significantly increased with increasing initial height, while its minimum velocity and time of reaching the maximum velocity decreased during the same impact process. With increment of tuber mass, its impact velocities and time of reaching the maximum velocity presented linear change, but the bruise volume nonlinearly changed. The relationships among tuber temperature and impact characteristic parameters were in accordance with linear relationships. The 65 Mn-rubber rod can notably reduce potato impact damage because of its cushioning effect. Potato bruise volume can be predicted based on the maximum and minimum velocity.

RESUMO Um estudo foi realizado para investigar a relação entre os fatores (altura inicial, massa de tubérculo, temperatura de tubérculo e impacto material) e as variáveis características do impacto (velocidade e volume da lesão), determinado através do equipamento de teste de impacto de pêndulo. Verificou-se que o volume de contusão e a velocidade máxima aumentaram significativamente com o aumento da altura inicial, enquanto a velocidade mínima e o tempo de atingir a velocidade máxima diminuíram durante o mesmo processo de impacto. Com o incremento da massa do tubérculo, suas velocidades de impacto e tempo de atingir a velocidade máxima apresentaram alteração linear, mas o volume de contusão mudou não linearmente. Enquanto isso, as relações entre temperatura do tubérculo e parâmetros característicos de impacto foram de acordo com relações lineares. A haste de borracha de 65 Mn pode reduzir notavelmente os danos causados pelo impacto da batata devido ao seu efeito amortecedor. O volume de contusões de batata pode ser previsto com base na velocidade máxima e mínima.

ABSTRACT To improve the complex process of judging the degree of soil fragmentation during potato-soil separation and to establish a fast and effective judging method. Soil drop experiments were performed using sandy soil from the potato growing region of Hohhot, Inner Mongolia Autonomous Region, China. The effects of soil moisture content, hardness, volume, drop height, inclination of the separating sieve and composition of the separating sieve rod on soil fragmentation were investigated. The fractal dimension and image processing used to quantify soil fragmentation and scattering and obtain quantitative indicators of soil fragmentation. The results showed that the following factors influenced soil fragmentation in descending order of statistical significance: soil hardness, fall height and soil volume. The softer the soil was, the greater the fall height; the larger the soil volume was, the greater the fragmentation. Meanwhile the correlation between the two indicators is extremely high, simplifying assessment of the degree of soil fragmentation. This study clearly shows the influence of the intrinsic physical properties of soil and the external physical parameters of potato excavators on the characteristics of crushed soil. The results can provide a basis for improving the efficiency of potato-soil separation and designing more efficient devices for harvesting potatoes. potatosoil method Hohhot Region China content hardness investigated significance was high potatoes

ABSTRACT The need for clarity regarding the sieving characteristics of the potato-soil mixture, as provided by the swing separating sieve of a potato digger, as well as the derived problems of low potato transportation efficiency, a high potato damage rate and low potato unearthing rate, are the main reasons for this study. Dynamic tracking technology is proposed to collect the motion state of potatoes, during the process of potato and soil separation. Considering the potato conveying speed, potato unearthing rate and potato damage rate as indicators, while the sieving parameters (crank rotational speed, sieve inclination, crank radius and swing direction angle) are the influencing factors, an orthogonal regression test is carried out, where the response surface is used to analyze each factor, its influence on the screening index, and to optimize it accordingly. The test results show that there is a linear relationship between the screening parameters and indexes, with each parameter showing different contribution rates to the screening indexes. The best parameter combination is the crank rotational speed of 190 r /min, sieve inclination of 9.7°, crank radius of 40 mm and swing direction angle of 18.8°. The corresponding potato conveying speed, unearthing rate and damage rate is 0.713 m/s, 98.7% and 3.224%, respectively. After optimization, the potato conveying speed is 1.43 times higher, the unearthing rate is increased by 2.5% and the damage rate is reduced by 60%. The research results can provide theoretical support to the structural design of potato diggers.

ABSTRACT For the purpose of achieving the distribution of the potato-soil mixture and the appropriate parameters of the swing separating sieve, we conducted experiments using the 4SW-170 potato digger. The experiments consisted of two parts. In each part, the experimental factors were crank rotational speed, sieve inclination and machine forward speed. The difference is that the first part involved a single factor test, which selected the coverage of the potato-soil mixture as the evaluation indicator. In contrast, the second part involved an orthogonal test, which selected the obvious rate and damage rate as evaluation indexes. In the first part, it was observed that the coverage of the potato-soil mixture on the separating sieve reduced gradually with the increase in crank rotational speed and sieve inclination. Inversely, as the machine forward speed was raised, the coverage of the potato-soil mixture gradually increased. In the second part, when the crank rotational speed was 230 rpm, the sieve inclination became 21.1°, and the machine forward speed was 2.03 km . h-1; the optimal parameter combination was obtained. Under such conditions, the obvious rate of potato harvest could reach as high as 99.49%, and the damage rate of potato harvest could reach as low as 0.87%. The reported results may be of help in providing a reference for the design of the swing separating sieve on potato diggers.