Internal combustion engine cylinder block and manufacturing method

A cylinder block of an internal combustion engine, comprising:

• a cylinder block body made of a first material;
• and
• a cylinder liner cast in said cylinder block body, said cylinder liner made of a second material different from said first material, said cylinder liner having an engaging portion contacting a portion of said cylinder block body from outside in a radial direction of said cylinder liner;
• wherein said engaging portion comprises a hollow space formed in said cylinder liner, said hollow space having an opening in an outer surface of said cylinder liner, an area of said hollow space being greater than an area of said opening when viewed in a radial direction of said cylinder liner.

A cylinder block of an internal combustion engine, comprising:

• a cylinder block body made of a first material;
• and
• a cylinder liner cast in said cylinder block body, said cylinder liner made of a second material different from said first material, said cylinder liner having an engaging portion contacting a portion of said cylinder block body from outside in a radial direction of said cylinder liner;
• wherein said engaging portion includes a first protrusion and a second protrusion adjacent to said first protrusion, said first and second protrusions protruding outwardly from an outer surface of said cylinder liner, each of said first and second protrusions having an end portion extending in opposite directions toward each other in a direction of a longitudinal axis of said cylinder liner.

A cylinder block of an internal combustion engine, comprising:

• a cylinder block body made of a first material;
• and
• a cylinder liner cast in said cylinder block body, said cylinder liner made of a second material different from said first material, said cylinder liner having an engaging portion contacting a portion of said cylinder block body from outside in a radial direction of said cylinder liner;
• wherein said engaging portion includes a first protrusion and a second protrusion adjacent to said first protrusion, said first and second protrusions protruding outwardly from an outer surface of said cylinder liner, said first and second protrusions slanting toward each other.

A cylinder block of an internal combustion engine, comprising:

• a cylinder block body made of a first material;
• and
• a cylinder liner cast in said cylinder block body, said cylinder liner made of a second material different from said first material, said cylinder liner having an engaging portion contacting a portion of said cylinder block body from outside in a radial direction of said cylinder liner;
• wherein said engaging portion includes a circumferentially extending portion connected to an outer surface of said cylinder liner, said circumferentially extending portion being positioned a predetermined distance away from said outer surface of said cylinder liner in a radial direction of said cylinder liner, said circumferentially extending portion having a plurality of openings connecting outside and inside of said circumferentially extending portion.

A method for manufacturing a cylinder block of an internal combustion engine, comprising:

• a cylinder block body made of a first material;
• and
• a cylinder liner cast in said cylinder block body, said cylinder liner made of a second material different from said first material, said cylinder liner having an engaging portion contacting a portion of said cylinder block body from outside in a radial direction of said cylinder liner,
• said method comprising:
• a first step of placing a core in a predetermined position inside a mold, said core having an inner surface for forming said engaging portion;
• a second step of die matching a liner pattern with respect to said core, said liner pattern having a contour substantially the same as said cylinder liner other than a portion corresponding to said engaging portion, said liner pattern comprising a combination of a plurality of pieces so that said liner pattern is die matched by positioning each of said pieces in a predetermined position inside said core;
• a third step of forming an outer surface forming mold corresponding to an outer surface of said cylinder liner by filling a mold material in a cavity formed between said mold and each of said core and said liner pattern and solidifying the mold material in said cavity so as to unitize the mold material and said core;
• a fourth step of removing said liner pattern from said mold;
• a fifth step of placing an inner surface die in a predetermined position inside said outer surface forming mold, said inner surface die having a contour substantially the same as a contour of an inner surface of said cylinder liner;
• a sixth step of forming a liner forming mold by filling a mold material in said inner surface die so as to form an inner surface mold having a contour substantially the same as the contour of the inner surface of said cylinder liner and solidifying the mold material in said inner surface die so as to unitize said outer surface forming mold and said inner surface forming mold;
• and
• a seventh step of casting said cylinder liner by filling molten metal in a cavity formed by said outer surface forming mold and said inner surface forming mold of said liner forming mold;
• and
• an eighth step of insertion casting said cylinder block with said cylinder liner inserted in said cylinder block.