Abstract: There is provided a method for manufacturing a cylinder for an internal combustion engine by making use of an insert core, which makes it possible to manufacture the cylinder by a die casting method such as a high-pressure die casting method at low cost and in high accuracy.

Abstract: A method is provided for manufacturing a cylinder for an internal combustion engine, which makes it possible not only to manufacture the cylinder by a high-pressure die casting method at low cost and in high precision, but also to prevent relative misalignment among the scavenging port, suction port and exhaust port of the cylinder. This method is characterized by the steps of: preparing a cylinder liner made of an aluminum alloy pipe and provided with the scavenging port, and a bore-core die as well as cores for scavenging ducts both being uncollapsible and configured so as not to intrude into the scavenging ports; setting the cylinder liner in place in the bore-core die; and casting, by means of metal mold casting method, an aluminum alloy onto the outer peripheral surface of the cylinder liner to thereby mold a main body of the cylinder.

Abstract: There is provided a method for manufacturing a cylinder for an internal combustion engine by making use of an insert core, which makes it possible to manufacture the cylinder by a die casting method such as a high-pressure die casting method at low cost and in high accuracy.

Abstract: A cylinder and a method for manufacturing a cylinder for an internal combustion engine is provided which avoids the generation of a step portion at the scavenging port without necessitating enhanced precision of the positioning of the working tools or the working location. A raw cylinder body is cast-molded with the scavenging port portion thereof being left closed. Subsequently, this closed scavenging port portion is cut out (or opened) by means of cutting work, etc. The cutting out of the closed scavenging port portion is performed by widening the cylinder bore side thereof at predetermined angles to the planes of the inner wall of the hollow scavenging passageway formed contiguous to the closed scavenging port portion.

Abstract: A cylinder and a method for manufacturing a cylinder for an internal combustion engine is provided which avoids the generation of a step portion at the scavenging port without necessitating enhanced precision of the positioning of the working tools or the working location. A raw cylinder body is cast-molded with the scavenging port portion thereof being left closed. Subsequently, this closed scavenging port portion is cut out (or opened) by means of cutting work, etc. The cutting out of the closed scavenging port portion is performed by widening the cylinder bore side thereof at predetermined angles to the planes of the inner wall of the hollow scavenging passageway formed contiguous to the closed scavenging port portion.

Abstract: A method of manufacturing a cylinder for an internal combustion engine, which is manufactured by a process wherein a raw cylinder body having an insert core left remained therein is obtained using an insert core comprising a cylindrical body having almost the same outer diameter as the diameter of bore of the cylinder, and a scavenging port-forming portion projecting radially outward from the cylindrical body and having almost the same cross-sectional configuration as that of the scavenging port, the cylinder bore of the raw cylinder body thus obtained is then subjected to a boring to remove the cylindrical portion of the insert core, and the scavenging port-forming portion of the insert core which is left remained in the raw cylinder body is removed by making use of a press.

Abstract: A method of manufacturing a cylinder for an internal combustion engine, which is manufactured by a process wherein a raw cylinder body having an insert core left remained therein is obtained using an insert core comprising a cylindrical body having almost the same outer diameter as the diameter of bore of the cylinder, and a scavenging port-forming portion projecting radially outward from the cylindrical body and having almost the same cross-sectional configuration as that of the scavenging port, the cylinder bore of the raw cylinder body thus obtained is then subjected to a boring to remove the cylindrical portion of the insert core, and the scavenging port-forming portion of the insert core which is left remained in the raw cylinder body is removed by making use of a press.

Abstract: A core for use in a die casting process has a wood fiber material as a main ingredient. The core can be disintegrated by exerting an external force subsequent to the die casting process. The core can also be disintegrated by applying a softening agent to soften it subsequent to the die casting process. Further, the core can be made up of a stack of paper layers that are peelably removable from each other.