D型打结器割绳脱扣机构空间结构参数分析

针对D型打结器割绳脱扣机构空间结构参数复杂且设计要求不清等问题,通过对打结器割绳脱扣机构与其它机构进行运动学分析,建立了割绳脱扣机构的参数设计理论模型,描述了割绳脱扣机构与其它机构之间的参数匹配关系。分析了割绳脱扣机构结构参数对割绳脱扣动作的影响,并得出脱扣凹槽及割刀的设计尺寸要求。结果表明割绳脱扣机构回转中心与脱扣凹槽面的距离变化范围为27~35 mm,割绳脱扣机构回转中心与割刀安装面距离的变化范围为47~53 mm,割刀刀刃尺寸由脱扣凹槽位置尺寸决定。设计并试制了一种组合式割绳脱扣机构,该机构可实现多参数调节,便于对所求结构参数的考核验证。将设计的组合式割绳脱扣机构安装在已有打结器上进行打结试验,分别对每个参数进行单因素试验,共设计11个试验组。试验结果表明割绳脱扣机构空间运动模型准确可靠,计算的结构参数匹配合理。

Spatial Structure Parameter Analysis of Rope Cutting and Releasing Mechanism of D-knotter

Aiming to resolve the problem the space structure of rope cutting and releasing mechanism of knotter was very complex and the structure parameter influencing the motion of rope cutting and releasing was unknown. Kinematics analysis of rope cutting and releasing mechanism and other mechanism were carried out. The parametric design theory about rope cutting and releasing mechanism was established. The relationship of parameter matching between rope cutting and releasing mechanism and other mechanism was described. The important structure parameters influencing the motion of rope cutting and releasing were analyzed. The design requirements of rope releasing platform and cutting knife were calculated. The results showed that the distance between center of gyration of rope cutting and releasing mechanism and the rope releasing platform were 27~35mm, the distance between centre of gyration of rope cutting and releasing mechanism and the platform of rope cutting knife were 47~53mm, the cutting edge size of rope cutting knife was decided by the position size of platform of rope cutting knife. In order to verify the accuracy of the model, a modular rope cutting and releasing mechanism was designed and manufactured based on the range of key size of rope cutting and releasing mechanism. The designed rope cutting and releasing mechanism can adjust the position size and structure size of rope releasing platform and cutting knife, it was very convenient for the validation of structural parameters of rope cutting and releasing mechanism. The wheat straw baling test on the designed mechanism was conducted in the interior, eleven experimental groups were designed. Results showed that if the design size met the design requirements, the effect of rope cutting and releasing was good, otherwise the effect of rope cutting and releasing was poor. Therefore, it can be found that the calculating structural size parameters of rope cutting and releasing mechanism were confirmed to the requirements of D-knotter, and the model was accurate and it could guide the optimal design of D-knotter.