An iron-based sprayed coating for coating a bore inner surface of a cylinder block for an internal combustion engine. A coating surface contains pits, its pit amount is within a range of 0.01% to 2.1%, and an average roughness Ra of this coating surface is within a range of 0.01 μm to 0.15 μm. The cylinder block for an internal combustion engine includes a bore having this iron-based sprayed coating on its inner surface, and a cylinder block body having the bore. A sliding mechanism for an internal combustion engine includes this cylinder block for an internal combustion engine and a piston slidable with the bore of this cylinder block. The piston has a piston ring, and the piston ring has a chromium coating, a chromium nitride coating, or a diamond-like carbon coating at a sliding part with the bore.

A cylinder liner of the present invention is a cylinder liner mounted on a cylinder block and formed of flaky graphite cast iron, at least a nitrided layer is provided on an inner periphery of the cylinder liner, and a cross hatching section is formed on the inner periphery, a roughness curve of the inner periphery has a plateau honing shape, a ten-point average roughness Rz of the inner periphery pursuant to JIS B0601:1982 is 4.0 μm or less, and an average value of an area ratio of pits generated in the inner periphery is 8% or less.

A cylinder liner of the present invention is a cylinder liner mounted on a cylinder block and formed of flaky graphite cast iron, at least a nitrided layer is provided on an inner periphery of the cylinder liner, and a cross hatching section is formed on the inner periphery, a roughness curve of the inner periphery has a plateau honing shape, a ten-point average roughness Rz of the inner periphery pursuant to JIS B0601:1982 is 4.0 μm or less, and an average value of an area ratio of pits generated in the inner periphery is 8% or less.

An engine block has one or more bores configured for receiving one or more respective pistons; one or more coolant passages; and one or more lubricant passages. At least portions of the coolant passages and lubricant passages are disposed adjacent to and about the bores so as to cool the bores. The coolant passage portion extends over a first lengthwise portion of the bores and the lubricant passage portion extending over a second lengthwise portion of the bores. The first and second lengthwise portions are longitudinally spaced apart along the bores.

There is provided a cylinder device having optimal arrangement of fine textures and optimal surface roughness capable of reducing wear of a cylinder bore side and a piston ring by processing fine textures in an optimal selection region of the cylinder bore side to improve lubrication characteristics between the piston ring and the cylinder bore side while reducing engine oil consumption by processing surface roughness of the cylinder bore side to an optimal status.

There is provided a cylinder device having optimal arrangement of fine textures and optimal surface roughness capable of reducing wear of a cylinder bore side and a piston ring by processing fine textures in an optimal selection region of the cylinder bore side to improve lubrication characteristics between the piston ring and the cylinder bore side while reducing engine oil consumption by processing surface roughness of the cylinder bore side to an optimal status.

Provided is a method for preventing the accumulation of cylinder oil at scavenging ports of low-speed marine engines. An oil passage is provided on a cylinder wall inside a cylinder. The oil passage includes multiple oil storage grooves processed in a circumferential direction of the cylinder wall. The oil passage is formed by obliquely extending from the inner side of the cylinder wall to the outside of the cylinder in a radial direction of the cylinder. The scavenging ports are uniformly distributed in a circumferential direction of the cylinder wall, and each of the oil storage grooves is correspondingly processed at an upper portion of the scavenging port upper edge of the scavenging port. Each of the oil storage grooves has a shape matching the curved surface of the scavenging port upper edge.

Provided is a method for preventing the accumulation of cylinder oil at scavenging ports of low-speed marine engines. An oil passage is provided on a cylinder wall inside a cylinder. The oil passage includes multiple oil storage grooves processed in a circumferential direction of the cylinder wall. The oil passage is formed by obliquely extending from the inner side of the cylinder wall to the outside of the cylinder in a radial direction of the cylinder. The scavenging ports are uniformly distributed in a circumferential direction of the cylinder wall, and each of the oil storage grooves is correspondingly processed at an upper portion of the scavenging port upper edge of the scavenging port. Each of the oil storage grooves has a shape matching the curved surface of the scavenging port upper edge.

A cylinder liner of the present invention is a cylinder liner mounted on a cylinder block and formed of flaky graphite cast iron, at least a nitrided layer is provided on an inner periphery of the cylinder liner, and a cross hatching section is formed on the inner periphery, a roughness curve of the inner periphery has a plateau honing shape, a ten-point average roughness Rz of the inner periphery pursuant to JIS B0601:1982 is 4.0 μm or less, and an average value of an area ratio of pits generated in the inner periphery is 8% or less.

A cylinder liner of the present invention is a cylinder liner mounted on a cylinder block and formed of flaky graphite cast iron, at least a nitrided layer is provided on an inner periphery of the cylinder liner, and a cross hatching section is formed on the inner periphery, a roughness curve of the inner periphery has a plateau honing shape, a ten-point average roughness Rz of the inner periphery pursuant to JIS B0601:1982 is 4.0 μm or less, and an average value of an area ratio of pits generated in the inner periphery is 8% or less.