Abstract: A method of improving corrosion resistance of a cylinder cover including a port that is an intake port or an exhaust port. The cylinder cover is configured such that an annular cooling water passage is formed between an inner peripheral surface of the port and a valve seat ring when the valve seat ring is inserted in the port. The method includes forming a weld overlay layer on each of sealed regions of the inner peripheral surface of the port by laser metal deposition using a welding material made of a nickel-based alloy, a copper alloy, stainless steel, or a titanium alloy, the sealed regions being positioned at both sides of the cooling water passage, respectively.

Abstract: A method of improving corrosion resistance of a cylinder cover including a port that is an intake port or an exhaust port. The cylinder cover is configured such that an annular cooling water passage is formed between an inner peripheral surface of the port and a valve seat ring when the valve seat ring is inserted in the port. The method includes forming a weld overlay layer on each of sealed regions of the inner peripheral surface of the port by laser metal deposition using a welding material made of a nickel-based alloy, a copper alloy, stainless steel, or a titanium alloy, the sealed regions being positioned at both sides of the cooling water passage, respectively.

Abstract: A projection forming method forming a projection on the surface of a work and includes: forming a first bank by LMD such that the first bank surrounds a projection forming region on the surface of the work; forming a first layer on the projection forming region by the LMD such that the first layer covers the first bank; laminating at least one first height raising layer on the first layer by the LMD; forming a second bank by the LMD along a peripheral edge of the at least one first height raising layer; forming an intermediate base layer on the at least one first height raising layer by the LMD such that the intermediate base layer covers the second bank; and laminating at least one second height raising layer on the intermediate base layer by the LMD.

Abstract: A method of manufacturing an inclined structure extending in an oblique direction from a surface of a base metal includes: forming a base portion by stacking a plurality of build-up layers on the surface of the base metal, each of the plurality of build-up layers being formed by a plurality of beads, the base portion including a reference surface inclined at an opposite side of the oblique direction across a perpendicular line of the surface of the base metal; and forming a projecting portion by stacking a plurality of build-up layers on the reference surface of the base portion, each of the plurality of build-up layers being formed by a plurality of beads, the projecting portion extending in the oblique direction from the base portion.

Abstract: A spinning forming method includes: preparing a plate including a back surface at which a ring-shaped projection is formed along an outer peripheral edge of the plate, a ratio of a thickness at a reference position of the plate to a thickness at a tip end of the projection being 0.7 or less, the reference position being a position where an inclination of a portion of the back surface which portion extends toward the tip end of the projection is 45° or more; rotating the plate; moving a processing tool outward in a radial direction from an inner side of the projection to a position above the projection while pressing the processing tool against a front surface of the plate that is rotating; and locally heating a portion of the plate against which portion the processing tool is pressed.

Abstract: In a spinning forming method, a plate including a peripheral portion at which a ring-shaped projection is provided is used, the projection projecting in a thickness direction of the plate. Further, while rotating the plate, a transform target portion of the plate is locally heated, and a processing tool is pressed against the transform target portion to transform the plate. According to this configuration, a heat capacity of the peripheral portion of the plate can be increased. With this, when heating the vicinity of the peripheral portion of the plate, the peripheral portion can be prevented from becoming high in temperature. As a result, deformation of the peripheral portion of the plate can be suppressed.

Abstract: A spinning forming method includes: preparing a plate including a back surface at which a ring-shaped projection is formed along an outer peripheral edge of the plate, a ratio of a thickness at a reference position of the plate to a thickness at a tip end of the projection being 0.7 or less, the reference position being a position where an inclination of a portion of the back surface which portion extends toward the tip end of the projection is 45° or more; rotating the plate; moving a processing tool outward in a radial direction from an inner side of the projection to a position above the projection while pressing the processing tool against a front surface of the plate that is rotating; and locally heating a portion of the plate against which portion the processing tool is pressed.

Abstract: A method of manufacturing a preliminary formed body includes an ironing step and a thickening step. In the ironing step, a predetermined range of a plate is formed into a tapered shape in such a manner that while rotating the plate, a transform target portion of the plate is locally heated by induction heating, and a processing tool is pressed against the transform target portion. In the thickening step, a peripheral portion that is a distal end of the tapered shape of the plate is expanded inward in such a manner that while rotating the plate, the peripheral portion is locally heated, and a forming roller is pressed against the peripheral portion to push the peripheral portion in a direction orthogonal to a thickness direction of the peripheral portion.

Abstract: A spinning forming method includes a first forming step and a second forming step, in each of which a plate fixed to a main shaft is formed while being rotated. In the first forming step, a processing tool is brought into contact with a first main surface of the plate to form a first level-changing portion extending from the first main surface toward a second main surface. In the second forming step, the processing tool is brought into contact with the second main surface at an outer peripheral side of the first level-changing portion to form a second level-changing portion extending in an opposite direction to the first level-changing portion.

Abstract: A projection forming method forming a projection on the surface of a work and includes: forming a first bank by LMD such that the first bank surrounds a projection forming region on the surface of the work; forming a first layer on the projection forming region by the LMD such that the first layer covers the first bank; laminating at least one first height raising layer on the first layer by the LMD; forming a second bank by the LMD along a peripheral edge of the at least one first height raising layer; forming an intermediate base layer on the at least one first height raising layer by the LMD such that the intermediate base layer covers the second bank; and laminating at least one second height raising layer on the intermediate base layer by the LMD.

Abstract: First, an annular first layer including a plurality of beads and having a width that is not less than twice a width of the bead is formed by laser metal deposition on a peripheral surface of a base metal, the peripheral surface facing outward or inward in a radial direction. Next, a plurality of annular height raising layers each including a plurality of beads are stacked on the first layer by the laser metal deposition. According to this configuration, an axisymmetric body including a flange portion having a relatively wide width can be manufactured while making a heat affected zone in the base metal extremely small.

Abstract: A spinning forming device includes: a rotating shaft that rotates a plate to be formed; a processing tool that presses a transform target portion of the plate to transform the plate; and a heater that locally heats the transform target portion by induction heating. The heater includes an electric conducting pipe, and the electric conducting pipe includes a coil portion extending in a circumferential direction of the rotating shaft and having a doubled circular-arc shape facing the plate. A cooling liquid circulates through the electric conducting pipe by a circulating device.

Abstract: A sliding surface located to one side in the axial direction relative to the axially central position of a rotary shaft is supported by the slide surface of a supply shaft in a slidable manner in the axial direction, the slide surface being the surface on which sliding occurs. The portion located to the other side in the axial direction side relative to the axially central position of the rotary shaft is fixed to an output shaft. The sliding surface is positioned on the surface of a hard coating, and the hard coating is positioned so as to cover a part of a substrate made of a GFRP. The slide surface is positioned on the surface of a hard coating, and the hard coating is positioned so as to cover a part of a substrate made of a GFRP.

Abstract: A spinning forming device includes: a rotating shaft that rotates a plate to be formed; a processing tool that presses a front surface of the plate while being moved outward in a radial direction of the rotating shaft; and a heater that is moved so as to be located on the same circumference as the processing tool and locally heats the plate by induction heating. The spinning forming device further includes a cooling device that cools the front surface of the plate.

Abstract: According to a spinning forming device, while a plate is rotated by a rotating shaft, a transform target portion of the plate is pressed by a processing tool and locally heated by a heater that performs induction heating. The heater includes a coil portion having a doubled circular-arc shape and is inclined by an inclining device relative to a direction from the rotating shaft toward the processing tool. A measuring unit measures distances each from the coil portion to an outer peripheral original portion of the plate at a plurality of measurement points distributed in a circumferential direction of the rotating shaft. A controller controls the inclining device based on a measurement result of the measuring unit such that an angle difference between the coil portion and the outer peripheral original portion becomes not more than a predetermined angle.

Abstract: A tube diameter expanding method includes: rotating a tube having one end fixed to a turntable about a center axis of the tube; inserting a rod-like roller which extends in an axial direction of the tube into the tube from another end of the tube, and bringing the rod-like roller into contact with a forming region extending from the other end to a predetermined position of the tube; heating the forming region of the tube; cooling at least a section located near the forming region and within a non-forming region extending from the predetermined position to the one end of the tube; and moving the rod-like roller in a state of contacting the forming region of the tube, in a direction from the one end of the tube toward the other end of the tube and outward in a radial direction of the tube.

Abstract: A spinning forming device according to one aspect, a receiving jig supporting a central portion of a plate to be formed is attached to a rotating shaft, and a transform target portion of the plate is pressed by a processing tool and locally heated by a heater that performs induction heating. The heater includes an electric conducting pipe in which a cooling liquid flows. The electric conducting pipe includes: a coil portion extending in a circumferential direction of the rotating shaft and having a doubled circular-arc shape facing the plate; and a pair of lead portions extending from the coil portion outward in a radial direction of the rotating shaft. Each of the pair of lead portions is retreated father away from the plate than the coil portion at its end portion adjacent to the coil portion.

Abstract: A spinning forming apparatus shapes a plate while rotating the plate around a rotational axis. The spinning forming apparatus includes: a holding member to which the plate is attached and which rotates the plate around the rotational axis; a processing tool configured to contact a first main surface of the plate to process and shape the plate; and a heater configured to heat the plate. The heater is arranged at the opposite side of the processing tool across the plate. The heater locally heats a position of a second main surface of the plate opposite to the first main surface, the position being located on a circumference around the rotational axis, the circumference being defined by a position, with which the processing tool contacts, of the plate.

Abstract: A spinning forming device includes: a receiving jig supporting a central portion of a plate to be formed; and a rotating shaft to which the receiving jig is attached. Further, the spinning forming device includes: a heater that locally heats a transform target portion of the plate by induction heating; and a processing roller that presses the transform target portion to transform the plate. Furthermore, the spinning forming device includes a cooling device and/or a lubricant supply device. The cooling device sprays a cooling gas toward the processing roller. The lubricant supply device supplies a lubricant onto the processing roller or to between the processing roller and the plate.

Abstract: A spinning forming device includes: a receiving jig supporting a central portion of a plate to be formed; and a rotating shaft to which the receiving jig is attached. The spinning forming device also includes: a heater configured to locally heat a transform target portion of the plate by induction heating; and a processing tool configured to press the transform target portion to transform the plate. The spinning forming device further includes a pair of holding rollers configured to sandwich an outside portion of the plate, the outside portion being located outside the transform target portion.