ローラ式ピッチングマシンの投球シミュレーションとその最適化に関する研究

摘要

ピッチングマシンは，野球の練習機あるいはバッティンrnグセンターなどで幅広く利用されている．現在，市販されrnているピッチングマシンは, 任意のコースにボールを投げrn分けることは難しい．このため，我々は三つのローラを用rnいた三ローラ式ピッチングマシンを発案し，その研究開発rnを行ってきた．%Pitching machine is widely used in venues ranging from professional baseball stadiums to batting centers. However, the throw performance of the pitching machines that have been developed so far for use during batting practice is not very high. Pitches such as the fastball, curveball and screwball are easily achieved by the pitching machine with three rollers which were developed by the authors. In this study, the moving behavior and contact stress state of the ball pitched with the three rollers type pitching machine is analyzed using dynamic finite element analysis software (ANSYS/LS-DYNA). The effect of the seam of a baseball to the throw accuracy is analyzed numerically. In the analysis, the finite element models of a detailed baseball with a seam and a pitching machine with three rollers are used. Additionally, convex and concave rollers are made and those are analyzed. From the analytical results, it is understood that the convex roller is higher than other rollers in throw accuracy. The convex roller geometry is optimized, and the optimum conditions (shapes and material properties) of the convex roller are decided. Moreover, the validity of the condition is confirmed by the throw experiment.