| 摘要 |
PURPOSE:To improve the accuracy of roundness in a cylinder bore yet better, by feeding a water jacket of a cylinder block with a cooling medium, and honing an inner surface of the cylinder bore. CONSTITUTION:A pump 8 is operated, and cooling water as a cooling medium is delivered to a water jacket 3 from a front water hole 4. And, a honing head is reciprocated inside a cylinder bore 2, making it grind the bore. At this time, a peripheral part of the cylinder bore 2 is uniformly cooled so that a heat rise due to friction is by far lesser as compared with the conventional method. Therefore, a thermal expansion value in either an X-Y direction or a Y-Y direction is also comes smaller, whereby a problem on anisotropy as to thermal expansion is in no case entailed there. Accordingly, the accuracy of roundness in the cylinder bore that has so far failed to improve more than a fixed level is made yet more improvable. |
