| 摘要 |
PURPOSE:To lighten the piston by a method wherein the contact surface lengths of piston pin boss at the explosion force receiving side are reduced by the same ratio as the increase ratio of strength due to a reinforcing fiber and further the contact surface lengths of piston pin boss at the inertia force receiving side are reduced by the same ratio as the ratio of the inertia force to the explosion force in addition to the increased ratio of strength due to the reinforcing fiber. CONSTITUTION:The piston pin bosses 3 and 3 are extending downwards from a piston head 2, independent to a piston skirt 4, and reinforced with the reinforcing fiber such as carbon fiber, silicon carbide or the like. The contact surface lengths l2' between the piston pin boss 3 and the upper side of a piston pin 5 at the receiving side of the explosion force P are reduced by the same ratio as the increased ratio of strength due to the reinforcing fiber 9. Furthermore, the contact surface lengths k2' between the piston pin boss 3 and the lower side of the piston pin 5 at the receiving side of the inertia force F are reduced by the same ratio as the ratio of the inertia force F to the explosion force P in addition to the increase ratio of strength due to the reinforcing fiber 9. According to the method described above, the length of the piston pin 5 can be shortened to reduce the weight thereof and as well as the weight of the piston pin boss part 3 can be lightened due to the contact surface lengths between the piston pin boss 3 and the piston pin 5 being shortened. |
