| 摘要 |
<p>Mechanical and structural problems that occur in stems are resolved by evenly stacking an FRP material to make it possible to maintain desired strength, proof stress, and rigidity. When a stem (8) is placed in a flat state, the stem (8) comprises the following structural elements made from FRP: an upper outer shell (4U), a main structure upper half (3U), a main structure lower half (3L), and a lower outer shell (4L). The FRP structural elements are integrated into one piece by stacking the FRP structural elements and applying heat and pressure to the FRP structural elements to melt resins impregnated in the FRP structural elements. Each of the upper and lower outer shells is a curved prepreg sheet formed by impregnating ±45-degree oriented carbon fiber with a thermoplastic resin, and each of the main structure upper and lower halves is a flat stacked part in which prepreg sheets formed by impregnating carbon fiber with a thermoplastic resin are stacked. Overlapping sections (5) of the upper and lower outer shells are formed such that the left and right portions of a main structure (3) formed by integrating the main structure upper and lower halves (3U, 3L) does not have a stepped outer surface.</p> |
