Abstract: A chemical surface treatment method of a metal improves bonding of different materials in which first pores are formed in the surface of the metal and second pores are formed locally in the surfaces of the first pores by appropriately setting the number of repetitions of alkali treatment and acid treatment, the concentrations of treatment solutions, and treatment temperatures and times using the treatment solutions. The method includes performing the alkali treatment by immersing the metal in a base solution, so as to form first pores in a surface of the metal. The method further includes performing the acid treatment by immersing an alkali-treated result product in an acid solution, so as to form second pores locally in surfaces of the first pores.

Abstract: A method for manufacturing a sandwich panel for a vehicle includes: etching a sheet, which etches one surface of a metal sheet; pressing the sheet, which forms a pattern of a specific shape on the one surface of the metal sheet; laminating a pair of the metal sheets; and performing injection-molding by injecting a plastic resin into the laminated pair of the metal sheets. The method may improve the bonding performance of the sandwich panel, thereby improving the degree of freedom of shape due to the press-molding.

Abstract: An exhaust manifold heat dissipation cover coupling device for thermal stress and vibration deflection is proposed. The device has a function of preventing wear of a heat dissipation cover to couple an exhaust manifold heat dissipation cover, the device being able to improve the durability of various parts including a heat dissipation cover by attenuating multi-directional vibration that is transmitted from an exhaust manifold when the heat dissipation cover is installed outside the exhaust manifold, being able to prevent damage to parts due to thermal stress by flexibly coping with thermal deformation such as thermal contraction or thermal expansion even if the thermal deformation is generated by high-temperature heat transmitted from the exhaust manifold, and being able to prevent frictional damage of the heat dissipation cover due to friction by a component that slides to attenuate vibration.

Abstract: A method for manufacturing a sandwich panel for a vehicle includes: etching a sheet, which etches one surface of a metal sheet; pressing the sheet, which forms a pattern of a specific shape on the one surface of the metal sheet; laminating a pair of the metal sheets; and performing injection-molding by injecting a plastic resin into the laminated pair of the metal sheets. The method may improve the bonding performance of the sandwich panel, thereby improving the degree of freedom of shape due to the press-molding.

Abstract: A method of casting a casting product having tubular flow passages includes: attaching a cast-in pipe insert, having outer and inner fixing members to which both ends of pipes are coupled, respectively, to a fixed mold; assembling a movable mold with the fixed mold; injecting a molten metal into a cavity defined inside the fixed and movable molds; ejecting a casting product from the assembled molds after injecting the molten metal; and removing the outer and inner fixing members from the casting product.

Abstract: An exhaust manifold heat dissipation cover coupling device for thermal stress and vibration deflection is proposed. The device has a function of preventing wear of a heat dissipation cover to couple an exhaust manifold heat dissipation cover, the device being able to improve the durability of various parts including a heat dissipation cover by attenuating multi-directional vibration that is transmitted from an exhaust manifold when the heat dissipation cover is installed outside the exhaust manifold, being able to prevent damage to parts due to thermal stress by flexibly coping with thermal deformation such as thermal contraction or thermal expansion even if the thermal deformation is generated by high-temperature heat transmitted from the exhaust manifold, and being able to prevent frictional damage of the heat dissipation cover due to friction by a component that slides to attenuate vibration.

Abstract: Disclosed are a holey plate, which improves the shape of punched holes so as to increase sound absorbing and insulating efficiency and durability, and a composite panel for sound absorption and sound insulation using the same. The holey plate used in the composite panel includes a base part, first bent parts configured to be bent from designated regions of the base part and to extend to be inclined so as to form a plurality of first punched holes by punching the designated regions of the base part in a thickness direction, and second bent parts configured to be bent from the first bent parts and to extend to be inclined so as to form second punched holes extending from the first punched holes, an angle of the second bent parts with the base part being smaller than an angle of the first bent parts with the base part.

Abstract: A method of casting a casting product having tubular flow passages includes: attaching a cast-in pipe insert, having outer and inner fixing members to which both ends of pipes are coupled, respectively, to a fixed mold; assembling a movable mold with the fixed mold; injecting a molten metal into a cavity defined inside the fixed and movable molds; ejecting a casting product from the assembled molds after injecting the molten metal; and removing the outer and inner fixing members from the casting product.

Abstract: A sound-permeable metal plate, which is a plate processed to have concavity and convexity formed thereon, may include: a plurality of cells protruding from the plate; and a flat base portion formed between the plurality of cells, wherein each of the cells includes a plurality of wall surface parts, which are bent on and protrude from the base portion, and a cover portion extending from end portions of the wall surface parts, and each of the cells has a straight line-shaped slit formed through the plate.

Abstract: A centrifugal casting apparatus for different materials may include a mold having a shape corresponding to a shape of an outer surface of a casting to be produced, and having a cavity receiving molten metals therein, a molten metal guide inserted into the mold and configured to guide the molten metals so that the molten metals are separately injected into the mold, a guide fixing support fixing the molten metal guide to a predetermined position, and a motor configured to rotate the mold around a rotation axis.

Abstract: Disclosed herein is a composite panel for sound absorption that may absorb and block noise. The composite panel may include: a first perforated panel comprising first embosses and first perforation groups formed in a predetermined pattern, wherein the first embosses are formed by forming a plurality of cells and the first perforation groups are formed by collecting a plurality of first perforated holes; an embossed panel comprising second embosses formed by forming the plurality of cells and coupled to the first perforated panel wherein the embossed panel is laminated with the first perforated panel; and a sound absorbing and insulating material inserted between the first perforated panel and the embossed panel.

Abstract: A centrifugal casting apparatus for different materials may include a mold having a shape corresponding to a shape of an outer surface of a casting to be produced, and having a cavity receiving molten metals therein, a molten metal guide inserted into the mold and configured to guide the molten metals so that the molten metals are separately injected into the mold, a guide fixing support fixing the molten metal guide to a predetermined position, and a motor configured to rotate the mold around a rotation axis.

Abstract: Disclosed herein is a composite panel for sound absorption that may absorb and block noise. The composite panel may include: a first perforated panel comprising first embosses and first perforation groups formed in a predetermined pattern, wherein the first embosses are formed by forming a plurality of cells and the first perforation groups are formed by collecting a plurality of first perforated holes; an embossed panel comprising second embosses formed by forming the plurality of cells and coupled to the first perforated panel wherein the embossed panel is laminated with the first perforated panel; and a sound absorbing and insulating material inserted between the first perforated panel and the embossed panel.

Abstract: A holey plate for sound absorption and insulation may include an array of through holes including a plurality of through holes having at least two different diameters, and the array of through holes being arrayed on the holey plate to form a predetermined pattern.

Abstract: An insulation structure of catalytic converter of vehicle according to an exemplary embodiment of the present invention includes an LNT converter. A connecting housing is provided such that a urea reducing agent is injected to the exhaust gas when it is needed. An SDPF converter reduces nitrogen oxide contained in the exhaust gas using the injected reducing agent, and SCR catalyst is coated on a filter. An insulation cover including inner surface contacts the LNT converter, the connecting housing and the SDPF converter and also includes an outer surface which is opposing surface to the inner surface and surrounds the LNT converter, the connecting housing and the SDPF converter. The insulation cover insulates heat generated from the LNT converter, the connecting housing and the SDPF converter. An insulation material is inserted and attached between the outer surface and the inner surface of the insulation cover.

Abstract: A sound-permeable metal plate, which is a plate processed to have concavity and convexity formed thereon, may include: a plurality of cells protruding from the plate; and a flat base portion formed between the plurality of cells, wherein each of the cells includes a plurality of wall surface parts, which are bent on and protrude from the base portion, and a cover portion extending from end portions of the wall surface parts, and each of the cells has a straight line-shaped slit formed through the plate.

Abstract: Disclosed is an insulation fiber composite. In particular, a surface of the insulation fiber composite is substantially improved such that a shape of three dimensions can be maintained as a heat resisting fiber and an insulation material are integrated. The insulation fiber composite of the present invention has excellent formability and surface property and comprises an insulation layer; and a pair of inorganic fiber layers. A first inorganic fiber layer of the pair is stacked on an upper surface of the insulation layer and a second inorganic fiber layer is stacked on a lower surface of the insulation layer, respectively. In particular, each the inorganic fiber layers has a greater planar surface area than a planar surface area of the insulation layer such that the insulation is not exposed to an exterior when the insulation layer and the pair of the inorganic fiber layers are stacked.

Abstract: A holey plate for sound absorption and insulation may include an array of through holes including a plurality of through holes having at least two different diameters, and the array of through holes being arrayed on the holey plate to form a predetermined pattern.

Abstract: An insulation structure of catalytic converter of vehicle according to an exemplary embodiment of the present invention includes an LNT converter. A connecting housing is provided such that a urea reducing agent is injected to the exhaust gas when it is needed. An SDPF converter reduces nitrogen oxide contained in the exhaust gas using the injected reducing agent, and SCR catalyst is coated on a filter. An insulation cover including inner surface contacts the LNT converter, the connecting housing and the SDPF converter and also includes an outer surface which is opposing surface to the inner surface and surrounds the LNT converter, the connecting housing and the SDPF converter. The insulation cover insulates heat generated from the LNT converter, the connecting housing and the SDPF converter. An insulation material is inserted and attached between the outer surface and the inner surface of the insulation cover.

Abstract: Disclosed is a multi-layered composite panel. The multi-layered composite panel comprises at least two sheets of thin plates with continuous waveform patterns having the same pitch and different heights in one direction are overlapped. In the multi-layered composite panel, an air layer is formed between the overlapping thin plates, orthogonal pressing portions, which divide the waveform patterns on the top and the bottom of the thin plates into the unit of triangle-patterned cell by being pressed orthogonally to cross each other on the top and the bottom of the thin plates overlapping in the orthogonal direction crossing the direction of the waveform patterns, are formed and an undercut portion is formed by pressing the centers of both sides connecting a groove and a ridge of each cell on the top and the bottom of the thin plates with opposite orthogonal pressing portions.