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本文分析了四杆机构作往复运动插秧机秧爪的轨迹,还用电子计算机求出了近似的速度和加速度,结果如下。1.求解爪尖的运动轨迹归结为计算四杆机构中间杆上一点的轨迹。用极坐标求出到主动杆原点的距离和角度,作为和主动杆旋转角的函数,由公式(1)～(6)求出。2.根据主动杆旋转时铰接点位置的变化,求出了四杆机构从动杆铰接点的速度和加速度近似值,并将其值与解析值进行比较,单倍字长的数值计算为0.1%,加速度用1%的准确度求出,双倍字长计算时,速度用2×10~(-8)%,加速度用6×10~(-7)%的准确度求出,可见这种近似法实质上是可行的。3.插拨秧苗和带土苗时,计算的轨迹、速度及加速度为图4～6。由此可知,对于轨迹、加速度、插秧的稳定性等方面,这种机构是良好的。4.探讨了各杆长度变化±10%时对于爪尖的最下端位置、入土速度、出土速度以及入土位置之间距离的影响(图7,表3)。对轨迹的影响大,对速度影响较小。有必要稍改变轨迹等因素时,用这些图表是方便的。
This paper analyzes the four-bar mechanism for reciprocating transplanter seedling paw trajectory, but also using computer to find the approximate velocity and acceleration, the results are as follows. 1. Solve the tip of the trajectory attributed to the calculation of four-bar mechanism on the middle of a point on the trajectory. The distance and angle to the origin of the active rod are determined by polar coordinates as a function of the angle of rotation of the active rod from equations (1) to (6). According to the change of the position of the hinge point when the active rod rotates, the approximate value of the velocity and acceleration of the articulated point of the driven rod of the four-bar mechanism is obtained and compared with the analytical value. The numerical value of the single word length is calculated as 0.1% , The acceleration is calculated by the accuracy of 1%. When the double word length is calculated, the speed is calculated using 2 × 10 -8% acceleration and 6 × 10 -7% accuracy. The approximation method is practically feasible. 3. Inserted seedlings and soil seedlings, the calculated trajectory, velocity and acceleration as shown in Figure 4-6. From this it can be seen that this mechanism is good for trajectory, acceleration, stability of transplanting and the like. 4. The influence of the lowest point of claw tip, the speed of soil entry, the velocity of soil excavated and the distance between the locations of soil into the earth (Fig. 7, Table 3) is discussed when the length of each pole is changed by 10%. Large impact on the trajectory, less impact on speed. It is convenient to use these charts when it is necessary to slightly change trajectories and other factors.