| 摘要 |
PURPOSE:To provide an arrangement for cylinder block of internal combustion engine, in which thickness of the cylinder block is varied at its skirt portion, whereby it is enabled to attenuate vibration of the cylinder block caused by impact forces of, for instance, piston slapping and thus to reduce noises caused by the cylinder block. CONSTITUTION:Thickness (t1) of wall surface 3a at the middle portion 1a of cylinder block 1 is unchanged along the entire width of the same, whereas thickness of the surface wall 3a at the upper portion of skirt portion 2 is changed gradually in the direction of its width. That is, thickness is t2 at its central portion and t3 at its opposite end portions. Further, thickness at the lower portion of the skirt portion 2 is t4 at its central portion and t5 at its opposite end portions. Thus, thickness of the surface wall 3a is changed gradually also in the lower portion of the skirt portion 2. Here, relationships between these thicknesses are t2<t1<t4, t3>t2 and t5>t3. By employing such an arrangement for the cylinder block, noises caused by the vibration can be lowered. |
