Abstract: This engine muffler has a sound absorbing material interposed between an internal tube and an external tube which is formed with a projection projecting toward the sound absorbing material along almost its entire periphery. When interposing the sound absorbing material between the internal tube and the external tube and drawing the end of the external tube for manufacturing the muffler, the projection projecting toward the sound absorbing material is formed on the external tube almost along its entire periphery after inserting the sound absorbing material between the internal tube and the external tube but before drawing the end of the external tube.

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: 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.