A-27 野球の『流し打ち』における打球速度を最大にする最適なインパクト(バットとボールとのインパクト)

抄録

The purpose of this study was to extract key impact parameters that determine the horizontal direction of batted ball trajectory in opposite-field hitting. Three-dimensional finite element analysis method was used to construct an impact model between a baseball and a wooden baseball bat, and a series of simulations with various bat swing direction and impact conditions were conducted. Horizontal bat angle was set -31〜20° and vertical bat angle was set 0〜51°, and each was analyzed at the 3° interval. The line of impact was set inclined in the range of 0〜40° with a 5° interval. The velocity and the angle from horizontal and from center line of the batted ball immediately after impact were determined for each simulated condition. The simulation model was validated by comparing the simulation outcome with experimental data obtained from opposite-field hitting practice performed by collegiate baseball players. The result showed that the horizontal angle of the bat at impact is the most impact parameter to determine the horizontal direction of batted ball trajectory in opposite-field hitting. In addition, the combination of the vertical bat angle and the angulation of the line of impact condition is also an important parameter. It is possible, therefore, to hit a ball toward a given horizontal direction with many different combination of horizontal bat angle, vertical bat angle and the angulation of the line of impact.