Abstract: The nozzle for cold spray (25) used in a cold spray apparatus (2) is configured to include a tubular nozzle main body (252) and a cooling jacket (253) that surrounds the nozzle main body (252) to form a flow path (25e) for refrigerant (R) between the nozzle main body (252) and the cooling jacket (253). The cooling jacket (253) is provided with a seal retaining portion (253c) that retains an O-ring (253b) for the flow path (25e). The seal retaining portion (253c) and the nozzle main body (252) are joined in a socket-and-spigot joint fashion.

Abstract: A film formation portion is formed on an annular edge portion along an opening portion (16a) of an intake port (16) or an opening portion (17a) of an exhaust port (17). The cross section, along the radial direction of the intake port (16) or the exhaust port (17), of the film formation portion, on which a metal film (5) is formed by spraying a raw material powder using a cold spray method, is formed in a groove shape that includes a flat bottom surface (G1) and a pair of side surfaces (G2) adjacent to the bottom surface.

Abstract: When forming valve seat coats at opening portions (16a1 to 16a8) of intake ports (16) provided at a cylinder block mounting surface (12a) of a semimanufactured cylinder head (3), the nozzle of a cold spray apparatus moves along a nozzle movement path for air intake (Inp1) that is set between any two of the plurality of opening portions (16a1 to 16a8), while continuing to spray a raw material powder. When forming valve seat coats at opening portions (17a1 to 17a8) of exhaust ports (17), the nozzle moves along a nozzle movement path for air exhaust (Enp1) that is set between any two of the plurality of opening portions (17a1 to 17a8), while continuing to spray the raw material powder.

Abstract: When forming valve seat coats at opening portions (16a1 to 16a8) of intake ports (16) provided at a cylinder block mounting surface (12a) of a semimanufactured cylinder head (3), the nozzle of a cold spray apparatus moves along a nozzle movement path for air intake (Inp1) that is set between any two of the plurality of opening portions (16a1 to 16a8), while continuing to spray a raw material powder. When forming valve seat coats at opening portions (17a1 to 17a8) of exhaust ports (17), the nozzle moves along a nozzle movement path for air exhaust (Enp1) that is set between any two of the plurality of opening portions (17a1 to 17a8), while continuing to spray the raw material powder.

Abstract: The nozzle for cold spray (25) used in a cold spray apparatus (2) is configured to include a tubular nozzle main body (252) and a cooling jacket (253) that surrounds the nozzle main body (252) to form a flow path (25e) for refrigerant (R) between the nozzle main body (252) and the cooling jacket (253). The cooling jacket (253) is provided with a seal retaining portion (253c) that retains an O-ring (253b) for the flow path (25e). The seal retaining portion (253c) and the nozzle main body (252) are joined in a socket-and-spigot joint fashion.

Abstract: A thermal spraying torch configured to spray a molten material onto a thermal sprayed surface of a work object and form a thermal sprayed coating has a discharge port configured to discharge the molten material, a discharge port periphery located on a peripheral edge of the discharge port on a front side in a discharge direction of the molten material and extending in the discharge direction, and an external surface continuous with a front end of the discharge port periphery. The discharge port periphery includes first section to which the molten material adheres more easily than to the external surface. The external surface includes a second section to which the molten material adheres less easily than to the discharge port periphery.

Abstract: Provided is a defect detection device capable of measuring the volume of surface defects. The defect detection device includes: an imaging device configured to image an image of an inspection object; a binarization processing unit configured to subject the image to first and second binarization processing by use of different first and second binarization thresholds, so as to calculate first and second sizes for an identical defect in the image; a ratio calculation unit configured to calculate a first ratio of the second size to the first size; and a depth determination unit configured to determine a depth of the defect depending on the first ratio.

Abstract: A thermal spraying torch configured to spray a molten material onto a thermal sprayed surface of a work object and form a thermal sprayed coating has a discharge port configured to discharge the molten material, a discharge port periphery located on a peripheral edge of the discharge port on a front side in a discharge direction of the molten material and extending in the discharge direction, and an external surface continuous with a front end of the discharge port periphery. The discharge port periphery includes first section to which the molten material adheres more easily than to the external surface. The external surface includes a second section to which the molten material adheres less easily than to the discharge port periphery.

Abstract: A thermally sprayed coating is formed on an inner surface of a cylinder bore of a cylinder block by using a thermal spray gun. The thermal spray gun is reciprocated along an axial direction in the cylinder bore while being rotated, and injects melted droplets generated by melting a wire made of a ferrous material from a nozzle at its end. At this time, a moving speed of the thermal spray gun along the axial direction into the cylinder bore is made equal-to or larger-than a predetermined value, and the number of reciprocating cycles of the thermal spray gun along the axial direction into the cylinder bore is made equal-to or larger-than a predetermined value.

Abstract: Provided is a defect detection device capable of measuring the volume of surface defects. The defect detection device includes: an imaging device configured to image an image of an inspection object; a binarization processing unit configured to subject the image to first and second binarization processing by use of different first and second binarization thresholds, so as to calculate first and second sizes for an identical defect in the image; a ratio calculation unit configured to calculate a first ratio of the second size to the first size; and a depth determination unit configured to determine a depth of the defect depending on the first ratio.

Abstract: Provided is a defect detection device capable of measuring the volume of surface defects. The defect detection device includes: an imaging device configured to image an image of an inspection object; a binarization processing unit configured to subject the image to first and second binarization processing by use of different first and second binarization thresholds, so as to calculate first and second sizes for an identical defect in the image; a ratio calculation unit configured to calculate a first ratio of the second size to the first size; and a depth determination unit configured to determine a depth of the defect depending on the first ratio.

Abstract: In a method for manufacturing a cylinder block provided with cylinder bores, the cylinder block is held by a clamp device, stress is generated in the cylinder block by a holding force of the clamp device to duplicate deformations of the cylinder bores after assembling hearing caps thereon, boring is carried out with the cylinder bores deformed in a condition where the stress is generated, and a thermally sprayed coating is formed, after the boring, on each inner surfaces of the cylinder bores deformed in the condition where the stress is generated. According to the method for manufacturing a cylinder block, superior cylindricity, after assembling the bearing caps, of the cylinder bores on each of which the thermally sprayed coating is formed can be brought, and workability degradation of finishing works (honing) for each inner surface of the cylinder bores (thermally sprayed coatings) can be restricted.

Abstract: In a method for a finishing work of a spray-coated surface, an inner surface of a cylindrical hollow member is roughened by forming a helical groove thereon. A thermal spray coating is formed on the inner surface that is roughened, and a finishing work is carried out by cutting the thermal spray coating along a helix of the groove by use of a cutting tool. According to the method for a finishing work, a finishing work of a thermal spray coating with non-uniform hardness can be carried out efficiently.

Abstract: Provided is a defect detection device capable of measuring the volume of surface defects. The defect detection device includes: an imaging device configured to image an image of an inspection object; a binarization processing unit configured to subject the image to first and second binarization processing by use of different first and second binarization thresholds, so as to calculate first and second sizes for an identical defect in the image; a ratio calculation unit configured to calculate a first ratio of the second size to the first size; and a depth determination unit configured to determine a depth of the defect depending on the first ratio.

Abstract: A sprayed coating forming method of forming a sprayed coating includes pre-heating a cylinder block defining a plurality of cylinders, supplying air into an enclosure that houses the cylinder block, inserting a spray gun sequentially into cylinder bores formed in the cylinder block while discharging the air at least from one side of the cylinder block, and spraying droplets of a molten metal onto an inner surface of each of the cylinder bores. The spraying includes spraying one of the cylinder bores first, then next spraying another of the cylinder bores that has at least one cylinder disposed between the another of the cylinder bores and the one of the cylinder bores sprayed first. The air flows around the cylinder block and also flows inside the cylinder bores.

Abstract: A cylinder block manufacturing method including: machining an inner surface of a cylinder bore (3) of a cylinder block (1) into a first shape different from a target shape before a bearing cap (7) is attached to the cylinder block (1) so that the inner surface of the cylinder bore (3) is deformed into the target shape by attachment of the bearing cap (7) to the cylinder block (1); and forming a thermal spray coating (5) on the inner surface of the cylinder bore (3) having the first shape.

Abstract: A cylinder block manufacturing method including: machining an inner surface of a cylinder bore (3) of a cylinder block (1) into a first shape different from a target shape before a bearing cap (7) is attached to the cylinder block (1) so that the inner surface of the cylinder bore (3) is deformed into the target shape by attachment of the bearing cap (7) to the cylinder block (1); and forming a thermal spray coating (5) on the inner surface of the cylinder bore (3) having the first shape.

Abstract: In a method for a finishing work of a spray-coated surface, an inner surface of a cylindrical hollow member is roughened by forming a helical groove thereon. A thermal spray coating is formed on the inner surface that is roughened, and a finishing work is carried out by cutting the thermal spray coating along a helix of the groove by use of a cutting tool. According to the method for a finishing work, a finishing work of a thermal spray coating with non-uniform hardness can be carried out efficiently.

Abstract: In a method for manufacturing a cylinder block provided with cylinder bores, the cylinder block is held by a clamp device, stress is generated in the cylinder block by a holding force of the clamp device to duplicate deformations of the cylinder bores after assembling hearing caps thereon, boring is carried out with the cylinder bores deformed in a condition where the stress is generated, and a thermally sprayed coating is formed, after the boring, on each inner surfaces of the cylinder bores deformed in the condition where the stress is generated. According to the method for manufacturing a cylinder block, superior cylindricity, after assembling the bearing caps, of the cylinder bores on each of which the thermally sprayed coating is formed can be brought, and workability degradation of finishing works (honing) for each inner surface of the cylinder bores (thermally sprayed coatings) can be restricted.

Abstract: A thermally sprayed coating is formed on an inner surface of a cylinder bore of a cylinder block by using a thermal spray gun. The thermal spray gun is reciprocated along an axial direction in the cylinder bore while being rotated, and injects melted droplets generated by melting a wire made of a ferrous material from a nozzle at its end. At this time, a moving speed of the thermal spray gun along the axial direction into the cylinder bore is made equal-to or larger-than a predetermined value, and the number of reciprocating cycles of the thermal spray gun along the axial direction into the cylinder bore is made equal-to or larger-than a predetermined value.