在发动机修理中,为了保证气缸中心线与曲轴轴承孔中心线的垂直度、各缸中心线的同面度及各缸中心距合乎标准,必须采用定位搪缸.但如何定位这个问题,是值得研究和探讨的。目前,比较多的修理部门,都是采用移动式搪缸机进行搪缸.它是以气缸体上平面作基准面、以缸孔定中心进行搪缸的。由于缸体上平面变形,一般在搪缸前还必须先修整上平面.但修整上平面时没有相对基准,只求消除上平面的不平度,这是不妥当的.上平面本身与曲轴轴承孔中心线不平行,以它为基准搪缸的气缸中心线与曲轴轴承孔中心线是不可能垂直的。如果以气缸体下平面为基准来修整上平面,这样仍然不能保证气缸中心线与曲轴轴承孔中心线垂直。生产厂是以下平面为基准进行搪缸的,但经使用后,缸体下平面变形很大,而 In the engine repair, in order to ensure the cylinder centerline and crankshaft bearing bore centerline perpendicularity, the sameness of each cylinder centerline and each cylinder center distance to the standard, must use positioning boring cylinder.But how to locate this problem is worth Research and discussion. At present, more repair departments, are using mobile boring machine boring machine. It is based on the plane of the cylinder body as a reference plane, cylinder centering cylinder boring. As the plane deformation of the cylinder, usually in the cylinder before the first plane must be trimmed, but when the plane is not trimmed relative benchmarks, just to eliminate the unevenness of the upper plane, it is not appropriate. The plane itself and the crankshaft bearing hole Centerline is not parallel to it as the base of the cylinder bore cylinder bore and crankshaft bearing bore centerline can not be vertical. If the plane under the cylinder block as a reference to trim the upper plane, so still can not guarantee that the cylinder centerline and crankshaft bearing hole centerline perpendicular. Production plant is based on the following plane cylinder boring, but after use, the cylinder under the plane deformation is large, and