田植機における植付爪の振動消去に関する研究

概要

論文の詳細を見る
An apparatus that measures vibrations originating in the motion of a rice transplanting mechanism consisting of the four bar linkage was produced. lts purpose was to make clear influences of the motion on the supporting member, that is, how the motion makes the member bibrate. The dynamic characteristics in a coupled system of this apparatus and mechanism were analyzed, and it was shown by theory and experiment that the fluctuating force caused by the motion had the most influence on the supporting member. Methods of controlling the fluctuating force were examined. The main results were as follows. 1) Influences of the fluctuating force may be estimated by assuming that the stational link is fixed on the inertial system. 2) The more the transplanting mechanism is removed from the center of rotation of the supporting member when the center is stational in inertial system, or from the center of gravity of the same member when the center is not stational, the larger becomes the influence of the fluctuating force,compared to that of the fluctuating torque on the crank shaft. 3) The optimum center of gravity to control the fluctuating force exists in every link. In type Ⅱ of the transplanting finger, according to optimization of the center of gravity on the coupler, the fluctuating force decreased about 40% by calculation. 4) To be balanced with maximum term in the fluctuating force expanded to Fourier series, the rotating additional mass may be determined by calculation methods. Concerning the phase of the mass, the experimental result agreed with the calcuation result, but concerning the radius of rotation of the mass, the former was acceptable being about 20% smaller than the latter. 5) Effects produced by the phase difference between one crank and the other crank were best at 180 degrees. Compared with the same phase, the fluctuating force sustained by the float in the rice transplanter decreased about 90%. It was impossible to detect the placement of pitching angle at 240 rpm (rotation speed of the crank shaft) in the experiment using the test bed. 6) The phase difference between two transplanting fingers should be 180/n degrees in to eliminate n dimensional higher harmonic term. In many transplanting fingers, fundmental wave's amplitude in maximum, and the higher the dimension becomes, the smaller the amplitude of higher harmonic becomes. Therefore it is good to control the fluctuating force so that the phase difference between two fingers is 180 degrees and between two sets (1 set =2 fingers) is 90 degrees. The practical arrangement and phase difference, however, must be determined allowing for a lateral rolling and the construction of seedling feeding mechanism in addition to the fluctuating force. 7) The position vector of resultant center of grevity in the transplanting finger moves in a circuit under conditions described by equation (80). Components of the fluctuating force are cycled sinusoidally. From equation (80),(83), the fluctuating force still becomes zero, and the position vector is constant. 8) The relationship in equation (80),(83) generally never makes the fluctuating torque change as a sine curve nor makes it to be zero. In a special case of the relationship (equation (74),(76)),only the effect of the inertial moment in each link remains, and the torque can be expressed by equation (90).
三重大学農学部の論文

田植機における植付爪の振動消去に関する研究

スポンサーリンク

概要

著者

関連論文

スポンサーリンク