Abstract: This invention relates to a muffler to be used in the exhaust system of an engine for automobiles, specifically to a muffler including a sound absorbing material interposed between the external tube and the internal tube, and a method of manufacturing the same. There are provided a durable and easy-to-manufacture engine muffler in which the sound absorbing material is reliably secured during use and during manufacturing process, and a method of manufacturing the same. The engine muffler comprising a sound absorbing material interposed between an internal tube and an external tube is formed with a projection projecting toward the sound absorbing material on the external tube along almost entire periphery thereof.

Abstract: This invention relates to an engine exhaust system for automobiles or the like; and more specifically, to an exhaust system having a crook of a generally U-shape at the mid section of the pipe line constituting the exhaust system. Even when a U-shaped crook is provided at the mid section of the pipe line constituting an exhaust system described above, the flowing resistance of exhaust air can be reduced to a minimum value to prevent the back pressure from being applied to the engine or lowering of the output of the engine. The engine exhaust system is such that the U-shaped crook forms a gentle curve so that the cross sectional area of the internal space of the U-shaped crook near the top portion is at least 1.3 times the minimum cross sectional area of the internal space of the pipe line having the U-shaped crook.

Abstract: This invention is concerned with an apparatus for bending a hollow double-structured pipe for use in an exhaust pipe of an internal combustion engine, for example, and aims at providing such hollow double-structured pipe which is capable of effecting favorable bending work, even in the case of using an inner pipe of a thin wall thickness.

Abstract: The invention is concerned with a flexible joint to be used for the exhaust system of an internal combustion engine in, for example, automobile, etc., and aims at providing such flexible joint which has good durability and is easy in assembling the structural parts and in setting the spring constant.

Abstract: Disclosed is an apparatus for bending a hollow double structured pipe, which is simple in construction, and is capable of putting into practice easily the continuous, two- or three-dimensional bending work.

Abstract: Disclosed is a method for electroless metal deposition, which comprises steps of: forming, on the surface of a non-conductive body to be plated, a coating of a resin composition for the electroless metal deposition containing therein a polymer (A) having a chemical structure of at least one compound selected from the group consisting of the below-listed (a), and at least one compound selected from the group of the below-listed (b)1 and (b)2; applying a negative electrostatic voltage to the film coating of the resin composition at a temperature level above the glass transition point of said resin composition; thereafter removing the applied voltage at a temperature lower than the glass transition temperature; and successively carrying out the metal deposition steps inclusive of the catalyst imparting step and the activating step:(a) a chemical structure, in which a part of hydrogen in the main chain of polymer is substituted with the halogen group or the nitrile group, and a chemical structure having a double