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: 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: 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: 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.

Abstract: An engine block coating system for applying a coating to an engine block includes a work stand, a coating gun, and a first nozzle. The work stand supports the engine block. The coating gun discharges coating on an inner surface of a first cylinder bank. The first nozzle discharges gas from a second cylinder bank to a crankcase side of the first cylinder bank and the second cylinder bank such that the second cylinder bank is shielded from the coating. The coating gun and the first nozzle are arranged relative to each other such that gas discharged by the first nozzle is discharged toward the coating to alter a direction of the coating by the gas discharged by the first nozzle directly contacting the coating such that the coating would otherwise contact the cylinder bore of the second cylinder bank upon stopping discharge of the gas by the first nozzle.

Abstract: A cylindrical internal surface processing apparatus has an internal diameter measuring device and a controller. The internal diameter measuring device measures an internal diameter of an internal cylindrical bore formed in a base member to obtain a measurement result of the internal diameter of the internal cylindrical bore. The controller includes a surface roughening control section and a quality determining section. The surface roughening control section controls operation of a surface roughening equipment to form a rough surface section and an internal diameter measuring surface section on the internal cylindrical bore. The internal diameter measuring surface section is smoother than the rough surface section.

Abstract: A cylindrical internal surface processing apparatus has an internal diameter measuring device and a controller. The internal diameter measuring device measures an internal diameter of an internal cylindrical bore formed in a base member to obtain a measurement result of the internal diameter of the internal cylindrical bore. The controller includes a surface roughening control section and a quality determining section. The surface roughening control section controls operation of a surface roughening equipment to form a rough surface section and an internal diameter measuring surface section on the internal cylindrical bore. The internal diameter measuring surface section is smoother than the rough surface section.

Abstract: An engine block coating system for applying a coating to an engine block includes a work stand, a coating gun, and a first nozzle. The work stand supports the engine block. The coating gun discharges coating on an inner surface of a first cylinder bank. The first nozzle discharges gas from a second cylinder bank to a crankcase side of the first cylinder bank and the second cylinder bank such that the second cylinder bank is shielded from the coating. The coating gun and the first nozzle are arranged relative to each other such that gas discharged by the first nozzle is discharged toward the coating to alter a direction of the coating by the gas discharged by the first nozzle directly contacting the coating such that the coating would otherwise contact the cylinder bore of the second cylinder bank upon stopping discharge of the gas by the first nozzle.

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: Before a thermally sprayed coating is deposited onto a cylindrical internal surface of a cylinder bore 3a rough surface 13 is formed to increase the adhesion of the thermally sprayed coating. After forming the rough surface is completed, an internal diameter measurement surface that is smoother than the rough surface is formed on an axial end section of the internal cylindrical surface. The internal diameter of the cylinder bore is measured at the internal diameter measurement surface with an internal diameter measuring instrument. An appropriate thickness for the thermally sprayed coating is determined based on the measurement result.