| 摘要 |
PURPOSE:To obtain a product having less casting defects with smaller man-hour for welding by casting a crank case body which is opened in the upper part of the space part and welding a separately manufactured top plate and intermediate plate to said open part thereby covering the crank case body. CONSTITUTION:A crank case 1 body which is opened in the upper part of the space part is cast with a construction in which the space part including an air feed chamber 1a, water chamber 1b, etc. is provided from above to the central part sandwiched by the right and left banks 10, 11 of the case 1. A top surface plate 2 made of a steel is full circumferentially welded to the upper side of the chamber 1a and an intermediate plate 3 made of a steel as a partition for the chambers 1a, 1b is similarly welded to the base metal of the case 1. Since the plates 2, 3 parts are opened according to the above-mentioned method, a substantially large riser is installed just above the partition wall of the case 1 and the generation of a shrinkage cavity is prevented in the stage of casting. |
