Abstract: In a water-based coating material, to be able to obtain a tough film having an excellent corrosion resistance even if an additive amount of zinc oxide particles is reduced less than that of conventional ones and obtain a tougher film having a much excellent corrosion resistance by coupling a great amount of carboxyl groups to a surface of zinc oxide particles when making the additive amount of zinc oxide particles equal to that of conventional ones.

Abstract: In a water-based coating material, to be able to obtain a tough film having an excellent corrosion resistance even if an additive amount of zinc oxide particles is reduced less than that of conventional ones and obtain a tougher film having a much excellent corrosion resistance by coupling a great amount of carboxyl groups to a surface of zinc oxide particles when making the additive amount of zinc oxide particles equal to that of conventional ones.

Abstract: A cylinder block as a main part of an engine block includes a cylinder barrel assembly block, a skeleton-like frame surrounding the outer periphery of the cylinder barrel assembly block and a plate-like rigid film member, within a fluid passage in the skeleton-like frame. The skeleton-like frame is integrally joined to the outer surfaces of left and right side walls of the assembly block along the crankshaft axis and includes crossbeam bone members, longitudinal beam bone members and post bone members which are rigid and unitarily assembled into a three-dimensional latticework structure. A cylinder head is integrally coupled to the deck surface of the cylinder block and a lower case is integrally coupled to the lower surface of the cylinder block, lateral outer surfaces of the block and lower case along the crankshaft axis being formed flush with each other in parallel with the cylinder bore axis.

Abstract: An oil pan structure for the cylinder block of an internal combustion engine for storing lubricating oil in the oil pan. A volume body submergible at least partly below the oil level for displacing a volume of oil when the oil is titled by displacement to one side in the oil pan as a result of the running condition of the motor vehicle having the engine with the oil pan structure, such as during turning, acceleration, deceleration or banking. The volume body has an inlet opening positioned near an allowable upper limit oil level for a predetermined maximum oil tilting condition for introducing into the volume body the lubricating oil which exceeds the allowable upper limit oil level. The oil pan structure also has an oil discharge passage from the lower portion of the volume body.