Abstract: The disclosure includes manufacturing a semimanufactured cylinder head (3) having a shielding curtain portion (16g) and spraying metal powder (P) onto an annular valve seat portion (16f) using a cold spray method to form a valve seat film (16b). The shielding curtain portion (16g) projects in an annular shape from an annular edge portion of an opening portion (16a) of an intake port (16) or an opening portion (17a) of an exhaust port (17) toward the center (C) of the port. The annular valve seat portion (16f) is located on an outer side of the port than the shielding curtain portion (16g).

Abstract: The disclosure includes manufacturing a semimanufactured cylinder head (3) having a shielding curtain portion (16g) and spraying metal powder (P) onto an annular valve seat portion (16f) using a cold spray method to form a valve seat film (16b). The shielding curtain portion (16g) projects in an annular shape from an annular edge portion of an opening portion (16a) of an intake port (16) or an opening portion (17a) of an exhaust port (17) toward the center (C) of the port. The annular valve seat portion (16f) is located on an outer side of the port than the shielding curtain portion (16g).

Abstract: A divider plate for two or more inlet ports provided in a cylinder head of an internal-combustion engine comprises divider portions that divides inside of the two or more inlet ports along an intake air flow, a side cast-in insert portion provided on at least one side portion located in a direction perpendicular to that of the intake air flow, that is enclosed by molten metal during casting of the cylinder head, an inner cast-in insert portion that is provided between the divider portions, that is enclosed by the molten metal during the casting of the cylinder head, and an inner accelerator formed in the inner cast-in insert portion, accelerates coagulation of the molten metal, wherein the inner accelerator has at least one of a plurality of holes, a concave portion, a convex portion, and a concave-convex portion, or a combination of a hole and a concave portion, a convex portion or a concave-convex portion.

Abstract: A divider plate for two or more inlet ports provided in a cylinder head of an internal-combustion engine comprises divider portions that divides inside of the two or more inlet ports along an intake air flow, a side cast-in insert portion provided on at least one side portion located in a direction perpendicular to that of the intake air flow, that is enclosed by molten metal during casting of the cylinder head, an inner cast-in insert portion that is provided between the divider portions, that is enclosed by the molten metal during the casting of the cylinder head, and an inner accelerator formed in the inner cast-in insert portion, accelerates coagulation of the molten metal, wherein the inner accelerator has at least one of a plurality of holes, a concave portion, a convex portion, and a concave-convex portion, or a combination of a hole and a concave portion, a convex portion or a concave-convex portion.

Abstract: A partition plate (tumble plate) for an intake port is previously placed in an intake port molding sand core (port core) for forming an intake port of a cylinder head, and cast-in as the cylinder head is cast-molded, to partition the intake port into a plurality of ports. The partition plate is provided with shift preventing portion that prevent positional shift relative to the intake port molding sand core.

Abstract: A partition plate for an intake port of a cylinder head to be manufactured by cast molding is preliminarily set prior to the cast molding in a sand core applied to form the intake port and then cast in by the cast molding to partition the intake port into a plurality of ports. The partition plate is provided with an intake-side distal end, a cylinder-side distal end, a pair of side edges continuous with the intake-side distal end and the cylinder-sided distal end and to be cast in by molten metal during the cast molding. Each of the pair of side edges having end faces facing in a thickness direction and a side end face continuous with the end faces. The partition plate is further provided with a promoter section provided on at least one of the side end face and the end faces of each of the pair of side edges to promote solidification of the molten metal.

Abstract: A partition plate (cast-in object plate member) is preliminarily set in an intake-port forming sand core, by which an intake port of a cylinder head is molded, and cast in during cast molding of the cylinder head for partitioning the intake port. The partition plate has both distal ends, spaced apart in a longitudinal direction, one of which corresponds to an intake-side distal end at which an acute-angled end face is formed to induce core breaking in a port core at an area closer to the intake-side distal end.

Abstract: A partition plate (cast-in object plate member) is preliminarily set in an intake-port forming sand core, by which an intake port of a cylinder head is molded, and cast in during cast molding of the cylinder head for partitioning the intake port. The partition plate has both distal ends, spaced apart in a longitudinal direction, one of which corresponds to an intake-side distal end at which an acute-angled end face is formed to induce core breaking in a port core at an area closer to the intake-side distal end.

Abstract: A partition plate (tumble plate) for an intake port is previously placed in an intake port molding sand core (port core) for forming an intake port of a cylinder head, and cast-in as the cylinder head is cast-molded, to partition the intake port into a plurality of ports. The partition plate is provided with shift preventing portion that prevent positional shift relative to the intake port molding sand core.

Abstract: A partition plate for an intake port of a cylinder head to be manufactured by cast molding is preliminarily set prior to the cast molding in a sand core applied to form the intake port and then cast in by the cast molding to partition the intake port into a plurality of ports. The partition plate is provided with an intake-side distal end, a cylinder-side distal end, a pair of side edges continuous with the intake-side distal end and the cylinder-sided distal end and to be cast in by molten metal during the cast molding. Each of the pair of side edges having end faces facing in a thickness direction and a side end face continuous with the end faces. The partition plate is further provided with a promoter section provided on at least one of the side end face and the end faces of each of the pair of side edges to promote solidification of the molten metal.