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In order to explore the effect of the reciprocating cutter's working parameters on cutting characteristics of cotton stalk as well as to optimize the working parameters of the reciprocating cutter, the cutting tests of cotton stalk under the double support condition were performed with a self-developed cutting test bench of cotton stalk. The samples were the ripe cotton stalks with the diameter of 11.7-13.2 mm and the moisture content of 31%-37%. The main test equipment included the self-developed cutting test bench of cotton stalk, a high-speed camera system and a digital camera. The self-developed cutting test bench of cotton stalk consisted of 3 parts: A header, a feeding device and a measurement control system. The cutting tests were grouped into the single factor tests, the response surface tests and the verifying tests. The testing factors were average cutting velocity (ranging from 0.6-1.0 m/s), cutting inclination angle (ranging from 3°-23°) and ratio of cutting velocity to feeding velocity (ranging from 1-2), and 5 levels was set for each factor. The response surface testing scheme designed with the central composite design (CCD) method was a three-factor five-level testing scheme. The response surface analysis method was used to analyze the testing dates and to optimize the working parameters of the cotton stalk reciprocating cutter. The results from the tests showed that the change trends of the objective values (the maximum cutting force per unit diameter and the cutting power per unit cutting area) with the changes of the testing factors were basically consistent with the results of the single factor tests. The effects of the average cutting velocity and the cutting inclination angle on the objective values were significantly different (P<0.01), and the effect of the ratio of cutting velocity to feeding velocity on the objective values was not significantly obvious (P>0.05), but its effect on the morphological structure of the cutting section of the stubble was significantly different. When the ratio of cutting velocity to feeding velocity ranged from 1.25 to 1.5, it was observed that the cotton stalk could be completely cut off by means of the high-speed camera system ant the cutting section was even and smooth, therefore, the quality of the cutting section was the best in the ratio range of from 1.25 to 1.5. It was concluded that the optimal combination of the working parameters of the reciprocating cutter for cutting cotton stalk was as follows: the average cutting velocity of 0.9 m/s, the cutting inclination angle of 12.7°, the ratio of cutting velocity to feeding velocity ranging from 1.25 to 1.5. According to the results from the response surface tests, a regression model was established, which described the cutting characteristics of cotton stalk under the double supports. On the basis of the results of the verifying tests, it was found that the results from the regression model were well consistent with the optimal results obtained from the response surface tests. Therefore, the regression model was fit under the experimental conditions. The results of this research can provide technical support for not only developing a cotton stalk cutter, but also designing the equipment with high efficiency and low energy consumption for harvesting hard stalk. [ABSTRACT FROM AUTHOR]

Knotter is in the key position of the rectangular baler, and it's working quality is in direct relation to the job performance of the baler. D type knotter is now used more widely in the rectangular baler, and most of them used in domestic are imported from abroad. It is not only expensive but inconvenient in use and maintenance because of the complicated organization. Therefore, a new clip bale knotter was developed in order to develop independent intellectual property rights and meet the needs of the country. The paper was focused on analyzing the structures and working principles of D type knotter of rectangular baler and food packaging clipper machine to form a new kind of knotter. The main innovation of the new design was that the impacting clip action replaced the original knotting action of D type knotter through the U type clip punching device. To evaluate the knotter device, the architecture and working principles of the clip bale knotter were described and some experimental results of knotter applicability were verified. The clip bale knotter was composed of two parts. One part was based on the fan-shape dentate cam disc of D type knotter, for which the original knotter hook and corresponding meshing teeth of the fan-shape dentate cam disc were dismantled and the clipping rope and cutting rope organization were retained. The other part was added with U type clip punching device, U type clip feed mechanism and the driving machinery of punching. By designing U type clip punching device, driving mechanism of punching as well as U type clip feed mechanism, combining the calculation of the motion sketch of the cam swing rod mechanism, the integration of the clip bale knotter was finished. When the knotter worked, rope was sent to the above of the clipping rope disc by the sending rope needle powered by spindle, then the clipping rope disc was rotated to grip the rope, and the swing shaft of the knotter organization was made to swing by spindle cam through the deep-groove ball bearing. By the cooperation between U type clip feed mechanism and related artifacts of the punching device, U type clip was impacted to form a taut knot in the rope. In the process, the cutter swang to be just above the rope knot, and cutting the rope would end the knotting process. The driving machinery of punching and U type punching device moved back with the work of the swing shaft return spring and pushing rope plate respectively. To test the knotter's applicability, a bedstand was made. The knotting rate was used as the judgment standard. Three kinds of normal U type clips and 3 kinds of ropes were chosen to do the orthogonal experiments. The experimental results showed that when the spindle rotation speed was determined to be 90 r/min, it finished impacting clip within 0.7 s, and the rate of knotting and locking of the new knotter reached 99% and 100% respectively. During the experiment, delivering rope, clipping rope, impacting rope and cutting rope operated at an appropriate time sequence which ensured the knotting process to be finished. Compared with D type knotter, the new device had simpler structure, lower manufacturing difficulty and cost, and the operation and maintenance were more convenient. The results show that the knotter design is feasible and lays the foundation for further optimizing the structure and working parameters of the knotter and its evaluation. [ABSTRACT FROM AUTHOR]