Abstract: A laser drilling method is a laser drilling method for performing drilling on a workpiece by use of a laser beam. The laser drilling method includes, after machining a through hole by radiating the laser beam to the workpiece (S100), scanning with the laser beam centered around the through hole toward a radial direction while changing a radiation output of the laser beam (S200).

Abstract: A cladding method for a valve seat in a cylinder head blank includes a combustion chamber, an intake port or an exhaust port communicating with the combustion chamber, and an annular countersunk groove formed in an opening end of the port on the combustion chamber side, the method being for forming a cladding layer by irradiating metal powder supplied in the countersunk groove with a laser beam. A gas flow regulating wall is provided, which projects from the countersunk groove to an inner side of the countersunk groove and to the combustion chamber side, gas is sprayed during irradiating with the laser beam, and the gas is flown by the gas flow regulating wall from the inner side to an outer side of the countersunk groove.

Abstract: In a fuel injection valve having a nozzle hole plate wherein a nozzle hole is formed, the nozzle hole is formed with a flow path cross-section having an oval shape that has long axes and short axes, and the nozzle hole is formed having a tapered shape in which a flow path sectional area becomes larger from an entry-side open end portion toward an exit-side open end portion. The nozzle hole is formed such that a second angle that is an intersecting angle of opposing nozzle hole inner wall surface portions in an oblique section along the short axes of the entry-side open end portion and the exit-side open end portion, is greater than a first angle that is an intersecting angle of opposing nozzle hole inner wall surface portions in a longitudinal section along the long axes of the entry-side open end portion and the exit-side open end portion.

Abstract: In a powder supply method in cladding, an outlet pressure of a coaxial-nozzle side of a supply pipe connecting a feeder to a coaxial nozzle is set within a predetermined range, and powder is supplied from the feeder to the coaxial nozzle.

Abstract: Provided is a powder supply device that can stably supply powder from a main hopper to a powder supply means including a sub-hopper without requiring component replacement and the like. The powder supply device is provided with: a first piping that guides powder accumulated in a main hopper downward; a second piping that is connected to the first piping at a lower end portion thereof while intersecting with the first piping, and that guides the powder guided by the first piping to a sub-hopper; and a switching valve that pressure-feeds the powder temporarily deposited while forming an angle of repose at an intersecting portion of the first piping and the second piping, to the sub-hopper.

Abstract: A cladding method for a valve seat in a cylinder head blank includes a combustion chamber, an intake port or an exhaust port communicating with the combustion chamber, and an annular countersunk groove formed in an opening end of the port on the combustion chamber side, the method being for forming a cladding layer by irradiating metal powder supplied in the countersunk groove with a laser beam. A gas flow regulating wall is provided, which projects from the countersunk groove to an inner side of the countersunk groove and to the combustion chamber side, gas is sprayed during irradiating with the laser beam, and the gas is flown by the gas flow regulating wall from the inner side to an outer side of the countersunk groove.

Abstract: A laser drilling method is a laser drilling method for performing drilling on a workpiece by use of a laser beam. The laser drilling method includes, after machining a through hole by radiating the laser beam to the workpiece (S100), scanning with the laser beam centered around the through hole toward a radial direction while changing a radiation output of the laser beam (S200).

Abstract: In a fuel injection valve having a nozzle hole plate wherein a nozzle hole is formed, the nozzle hole is formed with a flow path cross-section having an oval shape that has long axes and short axes, and the nozzle hole is formed having a tapered shape in which a flow path sectional area becomes larger from an entry-side open end portion toward an exit-side open end portion. The nozzle hole is formed such that a second angle that is an intersecting angle of opposing nozzle hole inner wall surface portions in an oblique section along the short axes of the entry-side open end portion and the exit-side open end portion, is greater than a first angle that is an intersecting angle of opposing nozzle hole inner wall surface portions in a longitudinal section along the long axes of the entry-side open end portion and the exit-side open end portion.

Abstract: In a powder supply method in cladding, an outlet pressure of a coaxial-nozzle side of a supply pipe connecting a feeder to a coaxial nozzle is set within a predetermined range, and powder is supplied from the feeder to the coaxial nozzle.

Abstract: Provided is a powder supply device that can stably supply powder from a main hopper to a powder supply means including a sub-hopper without requiring component replacement and the like. The powder supply device is provided with: a first piping that guides powder accumulated in a main hopper downward; a second piping that is connected to the first piping at a lower end portion thereof while intersecting with the first piping, and that guides the powder guided by the first piping to a sub-hopper; and a switching valve that pressure-feeds the powder temporarily deposited while forming an angle of repose at an intersecting portion of the first piping and the second piping, to the sub-hopper.

Abstract: There is provided a method for manufacturing a cast iron member in which the production of gas defects such as blowholes or pinholes in a clad layer formed on the surface of a cast iron material can be reduced, and the generation of bead cracks in the clad layer can be restrained. In the method for manufacturing a cast iron member, including a step of forming the clad layer by melting a material for cladding by means of irradiation of a laser emitted from a laser irradiation device and by depositing the melted material on the surface of a part of the cast iron material, the step of forming the clad layer is performed by using a material the main ingredient of which is a copper element as the material for cladding so that when the clad layer is formed, a hardened layer having a thickness of 0.01 to 2.0 mm is formed on the surface of the cast iron material.

Abstract: There is provided a method for manufacturing a cast iron member in which the production of gas defects such as blowholes or pinholes in a clad layer formed on the surface of a cast iron material can be reduced, and the generation of bead cracks in the clad layer can be restrained. In the method for manufacturing a cast iron member, including a step of forming the clad layer by melting a material for cladding by means of irradiation of a laser emitted from a laser irradiation device and by depositing the melted material on the surface of a part of the cast iron material, the step of forming the clad layer is performed by using a material the main ingredient of which is a copper element as the material for cladding so that when the clad layer is formed, a hardened layer having a thickness of 0.01 to 2.0 mm is formed on the surface of the cast iron material.

Abstract: A covering is applied onto the outer surface of a pile including a steel pipe or the like to surround a predetermined length thereof so as to reduce a frost heaving force or negative friction acting on the pile in a frigid area. The covering is closely adhered by an adhesion layer the like to the pile over a given length thereof. This given length is between 0.5 and 5 m. The covering member includes a smooth-surfaced plastic covering or elastic covering. A rugged surface covering may be provided below the smooth surfaced covering.

Abstract: A frost damage proofed pile for installment in a frigid district where the pile is subjected to a freezing and frost heaving force, such as permanently or seasonally frozen soil terrain. A tubular sheath member is fitted over the pile surface and has a length longer than the thickness of an active or seasonally frozen soil layer of the terrain in which the pile is installed. At least a portion of said length of the pile is formed as an extensible section, and at least the lower end of said sheath member is secured to the pile at or below a position corresponding to the bottom region of said active or seasonally frozen soil layer. A fluid material is filled in a space defined between the pile and the sheath member. The frost heaving force caused to exist upon freezing of the active or seasonally frozen soil layer as well as negative friction caused to exist in summer are inhibited from affecting the pile due to sliding of the sheath member relative to the pile.