RESUMO O presente estudo visou investigar a força de atrito durante o processo de separação da batata do solo, bem como os fatores e padrões que influenciam essa força, além de estabelecer um sistema de teste para medir a força de atrito das batatas. Verificou-se que a massa da batata, a velocidade da manivela e a inclinação da peneira têm um impacto significativo na força de atrito ao longo da superfície da peneira. A interação entre a massa da batata e a velocidade da manivela tem o maior impacto na força de atrito ao longo da superfície da peneira. Além disso, sob os mesmos fatores - massa da batata entre 200-400 g, velocidade da manivela em 200 r min-1 e ângulo inclinado da peneira em 14.7°, a força de atrito das batatas ao longo da superfície com o solo é muito maior do que ao longo da superfície sem solo, variando entre 2,32 e 4,85. Verificouse Verificou se disso 200400 400 200-40 g 20 min1 min 1 min- 147 14 7 14.7° 232 2 32 2,3 485 4 85 4,85 20040 40 200-4 14.7 23 3 2, 48 8 4,8 2004 200- 14. 4,

ABSTRACT This study aimed to explore the friction force on potatoes in the process of potato-soil separation, its influencing factors and laws, and establish a testing system of potato-friction force. It was verified that the potato mass, crank speed, and sieve inclination significantly affected the potato’s friction force along the sieve surface. The interaction of potato mass and crank speed had the greatest effect on the friction force on the potato along the sieve surface. In addition, under the same factors of potato mass of 200~400 g, crank speed of 200 r min-1, and sieve inclination of 14.7°, the friction force of potato along the sieve surface with soil was much greater than that along the sieve surface without soil, ranging between 2.32 and 4.85. potatosoil separation laws potatofriction potatos s addition 200400 400 200~40 g 20 min1, min1 min 1, 1 min-1 147 14 7 14.7° 232 2 32 2.3 485 4 85 4.85 20040 40 200~4 min- 14.7 23 3 2. 48 8 4.8 2004 200~ 14. 4.

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 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.

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.

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.