Abstract: A method of manufacturing a cylinder block using a die apparatus wherein a columnar hole includes a bore in the cylinder block. The method includes the steps of abutting first and second split cores against an upper surface of a distal end core, the upper surface being located opposite the inner core, and introducing a molten metal into a cavity. An inner core is withdrawn to move the first and second split cores toward an axis. The first and second split cores are released from a formed product made of solidified molten metal. The split cores are removed from the formed product to form the bore, and an inner surface of the bore is cut.

Abstract: A mold device and a method of manufacturing a cylinder block. The mold device comprises a split core having two first split cores formed so that the tip parts thereof may be in a tapering shape, two second split cores installed between the first spilt cores, and an inner core is installed at the center part and pushing out the first split cores in the direction receding from the center axis thereof. When the inner core is pushed out to push out and position the first spilt cores, both end parts of the second split cores are brought into contact with the tip parts of the adjacent first split cores, and the outer side-faces of the first split cores and the outer side-faces of the second split cores form a cylindrical shape. When the inner core is raised, the first split cores and the second split cores are pulled to the axial center by first engagement pieces and second engagement pieces.

Abstract: A cylinder sleeve for being inserted in a cylinder bore defined in a block body of a cylinder block for an internal combustion engine. The cylinder bore includes a first annular recess and a second annular recess, and projecting walls. The cylinder sleeve comprises a hollow cylindrical body that is inserted into the cylinder block with at least part of an outer circumferential wall thereof adjacent to an inner circumferential wall of the projecting walls of the cylinder block, a larger-diameter portion projecting diametrally outwardly from an upper end of the outer circumferential wall of the hollow cylindrical body, a step disposed on an outer circumferential wall of said larger-diameter portion, by which the larger-diameter portions of adjacent cylinder sleeves are stacked, and a reduced-diameter portion provided by reducing a diameter of an inner circumferential wall of said hollow cylindrical body.

Abstract: A reduced-diameter portion (44) with a taper portion (46), a portion whose diameter is reduced in a tapered form, is provided on an inner peripheral wall of a cylinder sleeve (20a, 20b, 20c). On the outer peripheral wall of the top end of the cylinder sleeve (20a, 20b, 20c) is provided a large diameter portion (36a, 36b, 36c) projected outward along the diameter direction. Under the action of a friction stir welding tool (50), the cylinder sleeve (20a, 20b, 20c) inserted in a communication hole (16) of a block body (18) is joined to the block body (18) with the reduced-diameter portion (44) and the large-diameter portion (36a, 36b, 36c) in between. A closed deck-type cylinder block (10) is constructed with the process above. In the cylinder block (10), the gasket face (12) side of a water jacket (22) is closed by the large-diameter portion (36a, 36b, 36c).