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 forming method forms a coating film on a workpiece (e.g., a cylinder head) having a film-deposited portion (e.g., an annular valve seat part) by moving a nozzle of a cold spray device relative to the workpiece along a film formation trajectory having a film formation starting point and a film formation finishing point in which the film-deposited portion overlaps to form an overlapping portion. The coating film is formed by causing a raw material powder to collide in a solid-phase state with the workpiece and plastically deform. Also, the coating film on the film-deposited portion is further formed such that an inclination angle of an end part of the coating film relative to a surface of the film-deposited portion is 45° or less at the film formation starting point of the overlapping portion.

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: A cold spray device basically include at least a pedestal, a base plate, a motor, a spray gun, a high-pressure pipe and a rotating joint. The pedestal is configured to support a workpiece in a predetermined orientation. The base plate is disposed in a position away from the workpiece. The motor is arranged to cause the base plate to rotate about a rotational axis. The spray gun is mounted on the base plate so that a spray direction is directed toward the rotational axis. The high-pressure pipe guides a working gas to the spray gun. The rotating joint is provided to a base end of the high-pressure pipe. The high-pressure pipe is arranged along the rotational axis.

Abstract: A film forming method forms a coating film on a workpiece having at least two film-deposited portions which are not continuous with each other by moving a nozzle of a cold spray device relative to each other along a continuous movement trajectory. The movement trajectory includes at least two trajectories corresponding to the film-deposited portions and a connecting trajectory linking the trajectories of the film-deposited portions. The film-deposited portions are formed by continuously spraying a raw material powder from the nozzle by cold spraying to form a coating film on each of the plurality of film-deposited portions. A turnback point of the spraying is set on the connecting trajectory where a relative speed between the workpiece and the nozzle decreases in the movement trajectory.

Abstract: A film forming method forms a coating film on a workpiece (e.g., a cylinder head) having a film-deposited portion (e.g., an annular valve seat part) by moving a nozzle of a cold spray device relative to the workpiece along a film formation trajectory having a film formation starting point and a film formation finishing point in which the film-deposited portion overlaps to form an overlapping portion. The coating film is formed by causing a raw material powder to collide in a solid-phase state with the workpiece and plastically deform. Also, the coating film on the film-deposited portion is further formed such that an inclination angle of an end part of the coating film relative to a surface of the film-deposited portion is 45° or less at the film formation starting point of the overlapping portion.

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: 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 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: 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 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: A cylindrical internal surface processing method comprises forming a cylinder bore, roughening an upper section of the bore, depositing coating onto the bore, and machining a lower section of the bore and the coating. The forming of the cylinder bore includes forming the upper and lower sections with the lower section being axially spaced from the upper section and having an axial length greater than zero. The roughening creates a roughened surface such that a radially innermost edge of the roughened surface has an internal diameter smaller than an internal diameter of the lower section. The coating is deposited to cover the upper section and at least a portion of the lower section. The machining forms a tapered portion and a cylindrical portion, a radially outermost edge of the cylindrical portion having an internal diameter larger than that of a radially outermost edge of the roughened surface.

Abstract: An apparatus is provided to reduce the defect rate and decrease production yield by removing foreign objects even when the foreign objects are mixed in with the thermally sprayed film. The operation for forming thermally sprayed film on inner surface of cylinder bore is paused, and protrusions generated in the thermally sprayed film by foreign objects are detected by visual observation and removed by a manual operation. The thermal spraying operation is then performed until thermally sprayed film reaches the prescribed film thickness. After formation of the thermally sprayed film, a finishing operation is performed by means of honing.

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.