Abstract: An MMC cylinder liner comprises an inner tubular portion and an outer tubular portion. The inner tubular portion includes a metal matrix composite formed of a compact impregnated with an Al—Si alloy wherein the compact is made of a reinforcing material. The outer tubular portion is formed of the Al—Si alloy. The Si concentration of the Al—Si alloy impregnated into the compact of the inner tubular portion is different from the Si concentration of the Al—Si alloy of the outer tubular portion.

Abstract: A cylinder liner has an upper portion and a lower portion with respect to an axial direction of the cylinder liner. A high thermal conductive film is provided on an outer circumferential surface of the upper portion. A low thermal conductive film is provided on an outer circumferential surface of the lower portion. The cylinder liner reduces temperature difference of a cylinder along its axial direction.

Abstract: An MMC cylinder liner comprises an inner tubular portion and an outer tubular portion. The inner tubular portion includes a metal matrix composite formed of a compact impregnated with an Al—Si alloy wherein the compact is made of a reinforcing material. The outer tubular portion is formed of the Al—Si alloy. The Si concentration of the Al—Si alloy impregnated into the compact of the inner tubular portion is different from the Si concentration of the Al—Si alloy of the outer tubular portion.

Abstract: A cylinder liner for insert casting used in a cylinder block is provided. The cylinder liner includes an outer circumferential surface having a plurality of projections. Each projection has a constricted shape. A film of a metal material is formed on the outer circumferential surface and the surfaces of the projections. As a result, the cylinder liner ensures sufficient bond strength with the casting material of a cylinder block, and sufficient thermal conductivity with the cylinder block.

Abstract: A cylinder liner 2 is enveloped in a cylinder block through insert casting. The cylinder liner 2 includes a cylinder liner body 2a and a metal coating layer 8 formed on the body 2a through a cold spraying method. Since the metal coating layer 8 is formed in a non-molten and oxygen free state, few oxygen films or oxygen layers are formed on the surface of or in the interior of the metal coating layer 8. Thus, the thermal conductivity of the metal coating layer 8 is sufficiently high. As a result, the thermal conductivity from the metal coating layer 8 to the cylinder block is sufficiently high.

Abstract: A cylinder liner has an outer circumferential surface on which a film is formed. The film functions to form gaps between the cylinder block and the cylinder liner. Alternatively, the film functions to reduce adhesion of the cylinder liner to the cylinder block. The cylinder liner suppresses excessive decreases in the temperature of a cylinder.

Abstract: A cylinder liner for insert casting used in a cylinder block is disclosed. The cylinder liner has an outer circumferential surface, and upper, middle, and lower portions with respect to an axial direction of the cylinder liner. A high thermal conductive film is formed in a section of the outer circumferential surface that corresponds to the upper portion, and a low thermal conductive film is formed in a section of the outer circumferential surface that corresponds to the lower portion. The high thermal conductive film and the low thermal conductive film are laminated in a section of the outer circumferential surface that corresponds to the middle portion, thereby forming a laminated film portion. As a result, temperature difference along the axial direction of the cylinder is reduced.

Abstract: A cylinder liner for an engine cylinder block. A roughening process is performed only on an upper region of the outer surface of the cylinder liner. This increases adhesiveness with a sprayed layer at the upper region compared to a lower region of the liner outer surface. Therefore, difference in thermal conductance is produced in the axial direction of the cylinder liner. This maintains the wall temperature of the cylinder bore in an appropriate temperature range. Even if adhesiveness at the lower region of the liner outer surface is low, bottleneck-shaped projections are distributed on the liner outer surface. Thus, the bonding strength between the cylinder liner and the sprayed layer and the cylinder liner and the cylinder block via the sprayed layer is sufficient. This maintains the roundness of the cylinder bore and prevents fuel efficiency from being lowered by exhaust gas loss and mechanical loss.

Abstract: A liner outer surface is coated by a sprayed layer or a heterogeneous metal layer including a base metal phase and dispersed metal phases. During casting, liquid metal enters the sprayed layer from the dispersed metal phases and solidifies in a virtual vegetation root state. The surface of the cylinder block is thus rigidly fixed to the surface of the cylinder liner. In this case, a strong bonding force is produced between the cylinder block and the cylinder liner and high thermal conductivity is obtained compared to the prior art in which the liquid metal merely contacts a surface layer.

Abstract: A cylinder liner for insert casting and a method for manufacturing the cylinder liner are provided. The cylinder liner and the method are applied to cylinder blocks and improve the adherence and the bonding strength with a cylinder block material in a favorable manner. The cylinder liner satisfies the following requirements: (i) the height of projections 1P is in a range between 0.5 mm and 1.0 mm, inclusive; (ii) the number of the projections 1P is in a range between 5 and 60, inclusive, per cm2 on the outer circumferential surface; (iii) the area ratio of regions each encircled by a contour line of a height of 0.4 mm is in a range between 10% and 50%, inclusive; (iv) the area ratio of regions each encircled by a contour line of a height of 0.2 mm is in a range between 20% and 55%, inclusive; (v) the region each encircled by a contour line of the height of 0.4 are independent from each other; and (vi) the area of the regions each encircled by a contour line of the height of 0.4 mm is in a range between 0.

Abstract: A cylinder liner for insert casting and a method for manufacturing the cylinder liner are provided. The cylinder liner and the method are applied to cylinder blocks and improve the adherence and the bonding strength with a cylinder block material in a favorable manner. The cylinder liner satisfies the following requirements: (i) the height of projections 1P is in a range between 0.5 mm and 1.0 mm, inclusive; (ii) the number of the projections 1P is in a range between 5 and 60, inclusive, per cm2 on the outer circumferential surface; (iii) the area ratio of regions each encircled by a contour line of a height of 0.4 mm is in a range between 10% and 50%, inclusive; (iv) the area ratio of regions each encircled by a contour line of a height of 0.2 mm is in a range between 20% and 55%, inclusive; (v) the region each encircled by a contour line of the height of 0.4 are independent from each other; and (vi) the area of the regions each encircled by a contour line of the height of 0.4 mm is in a range between 0.

Abstract: A cylinder liner has an upper portion and a lower portion with respect to an axial direction of the cylinder liner. A high thermal conductive film is provided on an outer circumferential surface of the upper portion. A low thermal conductive film is provided on an outer circumferential surface of the lower portion. The cylinder liner reduces temperature difference of a cylinder along its axial direction.

Abstract: A cylinder liner has an outer circumferential surface on which a film is formed. The film functions to form gaps between the cylinder block and the cylinder liner. Alternatively, the film functions to reduce adhesion of the cylinder liner to the cylinder block. The cylinder liner suppresses excessive decreases in the temperature of a cylinder.

Abstract: A cylinder liner for insert casting used in a cylinder block is provided. The cylinder liner includes an outer circumferential surface having a plurality of projections. Each projection has a constricted shape. A film of a metal material is formed on the outer circumferential surface and the surfaces of the projections. As a result, the cylinder liner ensures sufficient bond strength with the casting material of a cylinder block, and sufficient thermal conductivity with the cylinder block.

Abstract: A cylinder liner for an engine cylinder block. A roughening process is performed only on an upper region of the outer surface of the cylinder liner. This increases adhesiveness with a sprayed layer at the upper region compared to a lower region of the liner outer surface. Therefore, difference in thermal conductance is produced in the axial direction of the cylinder liner. This maintains the wall temperature of the cylinder bore in an appropriate temperature range. Even if adhesiveness at the lower region of the liner outer surface is low, bottleneck-shaped projections are distributed on the liner outer surface. Thus, the bonding strength between the cylinder liner and the sprayed layer and the cylinder liner and the cylinder block via the sprayed layer is sufficient. This maintains the roundness of the cylinder bore and prevents fuel efficiency from being lowered by exhaust gas loss and mechanical loss.

Abstract: A cylinder liner 2 is enveloped in a cylinder block through insert casting. The cylinder liner 2 includes a cylinder liner body 2a and a metal coating layer 8 formed on the body 2a through a cold spraying method. Since the metal coating layer 8 is formed in a non-molten and oxygen free state, few oxygen films or oxygen layers are formed on the surface of or in the interior of the metal coating layer 8. Thus, the thermal conductivity of the metal coating layer 8 is sufficiently high. As a result, the thermal conductivity from the metal coating layer 8 to the cylinder block is sufficiently high.

Abstract: A cylinder liner for insert casting used in a cylinder block is disclosed. The cylinder liner has an outer circumferential surface, and upper, middle, and lower portions with respect to an axial direction of the cylinder liner. A high thermal conductive film is formed in a section of the outer circumferential surface that corresponds to the upper portion, and a low thermal conductive film is formed in a section of the outer circumferential surface that corresponds to the lower portion. The high thermal conductive film and the low thermal conductive film are laminated in a section of the outer circumferential surface that corresponds to the middle portion, thereby forming a laminated film portion. As a result, temperature difference along the axial direction of the cylinder is reduced.

Abstract: A liner outer surface is coated by a sprayed layer or a heterogeneous metal layer including a base metal phase and dispersed metal phases. During casting, liquid metal enters the sprayed layer from the dispersed metal phases and solidifies in a virtual vegetation root state. The surface of the cylinder block is thus rigidly fixed to the surface of the cylinder liner. In this case, a strong bonding force is produced between the cylinder block and the cylinder liner and high thermal conductivity is obtained compared to the prior art in which the liquid metal merely contacts a surface layer.

Abstract: A cylinder block (10) is such that a main body cylinder block (4; 404) and an outer cylinder block (6; 406) are molded separately. As a result, the portion of the die which is used to mold a water jacket (50; 450) does not need to be made thin, thereby increasing the life of the die. Further, cylinders (12; 412) are of a simple shape and the pressure in the axial direction of the cylinder (12; 412) is able to be dispersed substantially evenly between the cylinders (12; 412) and the outer cylinder block (6; 406), thus enabling the cylinders (12; 412) to be thin. Accordingly, there is an increased degree of freedom in design of the portion which forms the water jacket (50; 450). The water jacket (50; 450) and the cylinders (12; 412) can therefore both be made sufficiently thin, thereby contributing to a decrease in both the size and weight of the engine.

Abstract: A cylinder block of an internal combustion engine has a portion between a cylinder block body and a cylinder liner which is sealed against a coolant so as to prevent the coolant from entering a crank case. The cylinder block body is made of a first material. The cylinder liner is cast in the cylinder block body. The cylinder liner is made of a second material different from the first material. The cylinder liner has an engaging portion contacting a portion of the cylinder block body from outside in a radial direction of the cylinder liner.