Abstract: A three-dimensional powder bed fusion additive manufacturing apparatus includes a powder application device that includes a squeegee and applies a powder material to a build plate to form a powder layer, a camera that photographs a manufactured surface of the powder layer, and a determination unit that determines whether powder application failure of the powder material has occurred using an image photographed by the camera while or immediately after the squeegee passes through the manufactured surface.

Abstract: An apparatus includes a build plate, a powder application apparatus that applies metal powder onto the build plate to form a powder layer, a beam irradiation apparatus that irradiates the powder layer with an electron beam, and a control unit that controls the powder application apparatus and the beam irradiation apparatus. When the powder layer is preheated by irradiation with the electron beam, the control unit sets a beam size and an irradiation position of the electron beam such that lines of the electron beam do not overlap each other at least at a start of preheating, and controls the beam irradiation apparatus to gradually increase at least one of a beam current and the beam size of the electron beam from the start of preheating to an end of preheating.

Abstract: A three-dimensional PBF-AM apparatus includes: a build plate on which a powder material is spread in layers; and a beam irradiation device which irradiates the powder material spread on the build plate with a beam. The beam irradiation device divides a build region of the powder material spread on the build plate into a plurality of lines and performs beam scanning to melt the powder material in the build region line by line, and performs dummy scanning to scan the beam in a state that does not cause melting of the powder material between an end of beam scanning of an M-th (M is a natural number) line and a start of beam scanning of an (M+1)th line.

Abstract: A three-dimensional powder bed fusion additive manufacturing apparatus includes a powder application device that includes a squeegee and applies a powder material to a build plate to form a powder layer, a camera that photographs a manufactured surface of the powder layer, and a determination unit that determines whether powder application failure of the powder material has occurred using an image photographed by the camera while or immediately after the squeegee passes through the manufactured surface.

Abstract: A three-dimensional powder bed fusion additive manufacturing apparatus includes a determination unit that determines presence or absence of powder scattering in a second preheating step using at least a third image that is an image of a powder layer photographed by a camera after the second preheating step among a first image that is an image of the powder layer photographed by the camera after a first preheating step, a second image that is an image of the powder layer photographed by the camera after the powder application step, and the third image.

Abstract: A seal structure includes a mounting groove disposed in a first member and a packing unit housed in the mounting groove. The packing unit includes an inner circumferential mounting section and an outer circumferential sliding section. Both side surfaces of the packing unit are conical surfaces which are inclined such that their diameters gradually increase in a direction from the mounting section toward the sliding section and which are inclined in mutually opposite directions. The thickness of the packing unit increases in a gradual manner in the direction from the mounting section toward the sliding section, the thickness in the mounting section is the smallest, and the thickness in the sliding section is the largest.

Abstract: A sealing structure is configured in the following manner. When a packing having a pair of sealing portions formed at opposite edge portions of the outer peripheral surface thereof is installed in a land portion of a spool, the outside diameter of the packing is made smaller than the diameter of a slide surface of a spool hole. In a state in which the outer periphery of the land portion opposes the slide surface and a pressurized fluid is supplied from a gas supply channel to the first space of first and second spaces that are partitioned by the land portion, the edge portion of the packing positioned near the first space is elastically elongated in a radial direction due to pressure of the pressurized fluid and thereby narrows a gap formed between the first sealing portion and the slide surface of the spool hole or abuts the slide surface.

Abstract: A fluidic cylinder has a cylinder tube having a cylinder chamber defined in an interior thereof has a pair of cover members attached to respective ends of the cylinder tube. A piston is disposed displaceably along the cylinder chamber, and a piston rod is connected to the piston. The piston and the cylinder tube are formed with rectangular shapes in cross section, the piston includes a wear ring which is in sliding contact with an inner wall surface of the cylinder tube, and a magnet is incorporated in the wear ring. At least one of the cover members includes bolt holes therein, the bolt holes extending in at least two or more directions including a direction in which the piston is displaced, and fastening bolts are selectively inserted into the bolt holes to fix the at least one of the cover members with respect to another member.

Abstract: A packing has an outer circumferential surface and includes a pair of sealing parts located at opposite ends of the packing in a direction along an axis. A piston has a sliding face having a first recess groove. When in the first recess groove, the packing has an outside diameter smaller than the diameter of a slide-receiving face of a cylinder hole. The piston divides the cylinder hole into a pair of chambers. While a compressed fluid is supplied to either one of the chambers, a side edge of the packing adjacent to the chamber at a high pressure is stretched in a radial direction by elastic deformation due to the pressure of the compressed fluid, thus causing a sealing part adjacent to the chamber at the high pressure to reduce a gap formed with the slide-receiving face of the cylinder hole or come into contact with the slide-receiving face.