Abstract: A filter device 2 is provided with: a filter body 3 equipped with a filtering material 30; and a mesh-like filter cover 5 that is mounted to the filter body 3 in such a manner as to cover at least part of a filtering surface 32 of the filtering material 30. The filter cover 5 is provided with: a purification part 50 which includes multiple layers formed by folding a single sheet of metal mesh material and which has a rectangular shape that is substantially identical to that of the filtering surface 32 in a plan view; and a first leg 51 and a second leg 52 which intersect with the purification part 50 in a side view. The metal mesh material has a finely corrugated surface formed thereon. The entire outer peripheral edge 59 of the filter cover 5 is completely fitted within the filtering surface 32.

Abstract: A 3-dimensional object-forming apparatus is provided which may avoid lowering of irradiation efficiency of laser light due to fumes and so forth while avoiding lowering of quality of the formed object. A shroud 20 includes an inside partition wall portion 21 that demarcates an inside space S1 which extends from one end opening 202 to another end opening 206, and an outside partition wall portion 22 that opens in the other end opening 206 of a shroud 20 on an outside of the inside space S1 and demarcates, together with the inside partition wall portion 21, an outside space S2 which closes in a position closer to the one end opening 202 than the other end opening 206 of the shroud. A ventilation area of the inside space S1 in the other end opening 206 of the shroud 20 is larger than the ventilation area of the inside space S1 in an upstream portion closer to the one end opening 202 than the other end opening 206.

Abstract: A 3dimensional object-forming apparatus is provided which may avoid lowering of irradiation efficiency of laser light due to fumes and so forth while avoiding lowering of quality of the formed object. A shroud 20 includes an inside partition wall portion 21 that demarcates an inside space S1 which extends from one end opening 202 to another end opening 206, and an outside partition wall portion 22 that opens in the other end opening 206 of a shroud 20 on an outside of the inside space S1 and demarcates, together with the inside partition wall portion 21, an outside space S2 which closes in a position closer to the one end opening 202 than the other end opening 206 of the shroud. A ventilation area of the inside space S1 in the other end opening 206 of the shroud 20 is larger than the ventilation area of the inside space S1 in an upstream portion closer to the one end opening 202 than the other end opening 206.

Abstract: The three-dimensional object building apparatus includes a powder delivering unit that delivers a powder on an object building area, a powder flattening device that flattens the powder delivered from the powder delivering unit to form a powder layer, and a light beam radiating unit that is disposed above the object building area and radiates a light beam on the powder layer to sinter or melt solidify the powder for building an object. The three-dimensional object building apparatus also includes a transferring mechanism that moves the light beam radiating unit in three-dimensional directions, and a shroud that moves integrally with the light beam radiating unit and surrounds a space above an area of the powder layer that is smaller than the object building area around a radiation of the light beam. The powder delivering unit and the powder flattening device move integrally with the light beam radiating unit.

Abstract: The three-dimensional object building apparatus includes a powder delivering unit that delivers a powder on an object building area, a powder flattening device that flattens the powder delivered from the powder delivering unit to form a powder layer, and a light beam radiating unit that is disposed above the object building area and radiates a light beam on the powder layer to sinter or melt solidify the powder for building an object. The three-dimensional object building apparatus also includes a transferring mechanism that moves the light beam radiating unit in three-dimensional directions, and a shroud that moves integrally with the light beam radiating unit and surrounds a space above an area of the powder layer that is smaller than the object building area around a radiation of the light beam. The powder delivering unit and the powder flattening device move integrally with the light beam radiating unit.

Abstract: The three-dimensional object building apparatus includes a powder delivering unit that delivers a powder on an object building area, a powder flattening device that flattens the powder delivered from the powder delivering unit to form a powder layer, and a light beam radiating unit that is disposed above the object building area and radiates a light beam on the powder layer to sinter or melt solidify the powder for building an object. The three-dimensional object building apparatus also includes a transferring mechanism that moves the light beam radiating unit in three-dimensional directions, and a shroud that moves integrally with the light beam radiating unit and surrounds a space above an area of the powder layer that is smaller than the object building area around a radiation of the light beam. The powder delivering unit and the powder flattening device move integrally with the light beam radiating unit.

Abstract: The three-dimensional object building apparatus includes a powder delivering unit that delivers a powder on an object building area, a powder flattening device that flattens the powder delivered from the powder delivering unit to form a powder layer, and a light beam radiating unit that is disposed above the object building area and radiates a light beam on the powder layer to sinter or melt solidify the powder for building an object. The three-dimensional object building apparatus also includes a transferring mechanism that moves the light beam radiating unit in three-dimensional directions, and a shroud that moves integrally with the light beam radiating unit and surrounds a space above an area of the powder layer that is smaller than the object building area around a radiation of the light beam. The powder delivering unit and the powder flattening device move integrally with the light beam radiating unit.

Abstract: The tubular die of a centrifugal casting device of GNo.30 or above is employed suitably and powder is introduced while rotating, and an outer tubular body composed of that powder is provided. Subsequently, molten is introduced to the inner circumferential wall side of the outer tubular body while sustaining rotation of the tubular die thus forming an inner tubular body. The outer tubular body functions as a cooling metal (chiller) when the molten is cooled and solidified. In place of the outer tubular body composed of the powder, molten may be used for forming an outer tubular body or an outer tubular molding molded previously into tubular shape may be employed.

Abstract: A forming method wherein a billet (31, 66, 77, 87, 107, 128, 136, 144, 153, 77B, 77C) comprising a metal-based composite material (27) prepared by mixing an aluminum alloy (22) and a ceramic (15) is subjected to pressure forming to manufacture a formed article, which comprises carrying out the pressure forming by the use of different compression ratios for different portions of the formed article, wherein a compression ratio means the ratio of the height of a billet before the pressure forming to height of the billet after the pressure forming. The above forming method allows the manufacture of a formed article having different volume contents 8Vf) of the ceramic for different portions thereof.

Abstract: A brake drum includes a ring-shaped drum body, and a friction member secured to the inner circumferential surface of the drum body. Because the drum body is formed of a lightweight Al alloy and the friction member is formed of an Al-base composite material, the brake drum can be reduced in weight as a whole. Further, because the friction member, having projection portions formed on its outer periphery, is cast enveloped by molten metal of the Al alloy, the friction member and the drum body can be firmly fastened together. Thus, even when a great braking force is applied to the drum brake, the friction member can be prevented from being undesirably detached from the drum body.

Abstract: A brake drum has its strength elevated in its disk portion. The brake drum is formed from a composition having ceramics dispersed in a matrix. The disk portion has a high ceramic content and thereby a high strength. Its cylindrical portion has a ceramic content decreasing gradually from the outer edge of the disk portion.

Abstract: A brake drum has its strength elevated in its disk portion. The brake drum is formed from a composition having ceramics dispersed in a matrix. The disk portion has a high ceramic content and thereby a high strength. The brake drum has a disk portion and a cylindrical portion. The disk portion has a first ceramic content by volume and the cylindrical portion has a second ceramic content by volume that is less than the first ceramic content by volume as a result of the application of a higher compression ratio to the disk portion.

Abstract: A forming method wherein a billet (31, 66, 77, 87, 107, 128, 136, 144, 153, 77B, 77C) comprising a metal-based composite material (27) prepared by mixing an aluminum alloy (22) and a ceramic (15) is subjected to pressure forming to manufacture a formed article, which comprises carrying out the pressure forming by the use of different compression ratios for different portions of the formed article, wherein a compression ratio means the ratio of the height of a billet before the pressure forming to height of the billet after the pressure forming. The above forming method allows the manufacture of a formed article having different volume contents 8 Vf) of the ceramic for different portions thereof.

Abstract: An aluminum casting process using a casting mold in which after the cavity (25) is filled with an inert gas, magnesium is introduced into the cavity to have a magnesium layer (58a) deposited on the cavity wall. Then, nitrogen gas is introduced into the cavity to form magnesium nitride (58b) on the surface of the magnesium layer after the cavity wall is heated to a specific temperature. Then, molten aluminum is supplied to have an aluminum casting molded, while the surface of the molten aluminum (39) is reduced with magnesium nitride. This makes it possible to form magnesium nitride within a short time and decrease the amount of nitrogen gas as required.

Abstract: A cast-bonding process includes a magnesium coating step and a magnesium nitride-forming step. The magnesium-coating step is carried out by supplying gasified magnesium into a mold in which a cast-in insert formed from an aluminum alloy, or an aluminum-based composite material is set, so that magnesium may coat the insert. The magnesium nitride-forming step is carried out by supplying nitrogen gas into the mold so that the coating magnesium and nitrogen gas may react to form magnesium nitride. Then, a molten aluminum alloy is poured into the mold for cast-bonding the insert.

Abstract: An aluminum casting process using a casting mold in which after the cavity (25) is filled with an inert gas, magnesium is introduced in to the cavity to have a magnesium layer (58a) deposited on the cavity wall. Then, nitrogen gas is introduced into the cavity to form magnesium nitride (58b) on the surface of the magnesium layer after the cavity wall is heated to a specific temperature. Then, molten aluminum is supplied to have an aluminum casting molded, while the surface of the molten aluminum (39) is reduced with magnesium nitride. This makes it possible to form magnesium nitride within a short time and decrease the amount of nitrogen gas as required.

Abstract: A method of feeding a blank (31) by cutting a billet (11) for plastic working includes the steps of superimposing a plurality of annular members (15 to 18) having a coefficient of linear expansion smaller than that of the billet and an inside diameter slightly greater than the outside diameter of the billet on one another to assemble a tubular jig (12), inserting the billet into the assembled jig, heating the billet and the jig to a temperature at which the billet is half-molten, and cutting the billet into at least one blank by moving the annular members adjacent to one another in opposite directions. The cutting of the billet does not need a cutting tool, thus causing no wear of blades, and thereby allowing reduction in production cost. The billet can be cut into a plurality of pieces at a time, increasing productivity. Since the blanks can be fed together with the annular members, there is no need to reheat the blanks, providing increased productivity.

Abstract: An aluminum casting process using a casting mold in which after the cavity (25) is filled with an inert gas, magnesium is introduced into the cavity to have a magnesium layer (58a) deposited on the cavity wall. Then, nitrogen gas is introduced into the cavity to form magnesium nitride (58b) on the surface of the magnesium layer after the cavity wall is heated to a specific temperature. Then, molten aluminum is supplied to have an aluminum casting molded, while the surface of the molten aluminum (39) is reduced with magnesium nitride. This makes it possible to form magnesium nitride within a short time and decrease the amount of nitrogen gas as required.

Abstract: A brake drum has its strength elevated in its disk portion. The brake drum is formed from a composition having ceramics dispersed in a matrix. The disk portion has a high ceramic content and thereby a high strength. Its cylindrical portion has a ceramic content decreasing gradually from the outer edge of the disk portion.

Abstract: An aluminum casting method includes the step of applying in advance a mold release agent including magnesium to a mold surface. Thereafter, a nitrogen gas is injected into a cavity to cause reaction between the magnesium in the surface of the mold release agent and the nitrogen gas, thereby forming magnesium nitride. Since the nitrogen gas reacts only with the magnesium exposed in the surface of the mold release agent, the forming time of the magnesium nitride is reduced and also the amount of nitrogen gas used is reduced.