Exhaust device for internal combustion engine

An exhaust device for an internal combustion engine, comprising:

• an exhaust pipe;
• and
• an exhaust muffler connected to a downstream end of said exhaust pipe, said exhaust muffler extending from a portion thereof connected to said exhaust pipe rearward on a vehicle on which said exhaust muffler is installed;
• a plurality of expansion chambers defined in said exhaust muffler;
• an exhaust passage pipe extending through said expansion chambers for allowing exhaust gases from said exhaust pipe to flow therethrough;
• and
• an exhaust valve provided in said exhaust passage pipe for opening and closing said exhaust passage pipe to switch between flow passageways for exhaust gases,
• wherein said exhaust muffler is made up of a plurality of layers including said exhaust passage pipe and said expansion chambers provided around an outer periphery of said exhaust passage pipe,
• wherein said exhaust muffler includes a front assembly connected to said exhaust pipe and a rear assembly connected to a rear portion of said front assembly and sub-assembled separately from said front assembly,
• wherein said exhaust passage pipe includes a front exhaust passage pipe as part of said front assembly, with said exhaust valve being disposed in said front exhaust passage pipe, and a rear exhaust passage pipe as part of said rear assembly,
• wherein said front assembly includes said front exhaust passage pipe, a front muffler body disposed in covering relation to an outside of said front exhaust passage pipe to cooperate with said front exhaust passage pipe in making up double-walled pipes, and said exhaust valve,
• wherein said rear assembly includes said rear exhaust passage pipe and a rear muffler body disposed in covering relation to an outside of said rear exhaust passage pipe to cooperate with said rear exhaust passage pipe in making up double-walled pipes, and said front exhaust passage pipe connected to the downstream end of said exhaust pipe,
• wherein one of said expansion chambers is provided between said front exhaust passage pipe and said front muffler body;
• wherein others of said expansion chambers are provided between said rear exhaust passage pipe and said rear muffler body;
• wherein said front muffler body has an outside diameter smaller than an outside diameter of said rear muffler body and has a constricted shape;
• and
• wherein said front exhaust passage pipe and said rear exhaust passage pipe are generally of the same diameter as each other.

An exhaust device for an internal combustion engine, comprising:

• an exhaust pipe;
• and
• an exhaust muffler connected to a downstream end of said exhaust pipe, said exhaust muffler extending from a portion thereof connected to said exhaust pipe rearward on a vehicle on which said exhaust muffler is installed;
• a plurality of expansion chambers defined in said exhaust muffler;
• an exhaust passage pipe extending through said expansion chambers for allowing exhaust gases from said exhaust pipe to flow therethrough;
• and
• an exhaust valve provided in said exhaust passage pipe for opening and closing said exhaust passage pipe to switch between flow passageways for exhaust gases,
• wherein said exhaust muffler is made up of a plurality of layers including said exhaust passage pipe and said expansion chambers provided around an outer periphery of said exhaust passage pipe,
• wherein said exhaust muffler includes a front assembly connected to said exhaust pipe and a rear assembly connected to a rear portion of said front assembly and sub-assembled separately from said front assembly,
• wherein said exhaust passage pipe includes a front exhaust passage pipe as part of said front assembly, with said exhaust valve being disposed in said front exhaust passage pipe, and a rear exhaust passage pipe as part of said rear assembly,
• wherein said front assembly includes said front exhaust passage pipe, a front muffler body disposed in covering relation to an outside of said front exhaust passage pipe to cooperate with said front exhaust passage pipe in making up double-walled pipes, and said exhaust valve,
• wherein said rear assembly includes said rear exhaust passage pipe and a rear muffler body disposed in covering relation to an outside of said rear exhaust passage pipe to cooperate with said rear exhaust passage pipe in making up double-walled pipes, and said front exhaust passage pipe connected to the downstream end of said exhaust pipe,
• wherein said exhaust muffler includes an exhaust device mount member by which said exhaust device is mounted on the vehicle;
• wherein said exhaust device mount member includes a front mount and a rear mount fixed respectively to said front muffler body and said rear muffler body, a front mount piece extending from said front mount upwardly of said front muffler body, and a rear mount piece extending from said rear mount and joining said rear mount to an upper end of said front mount piece;
• and
• wherein a vehicle mount to be mounted on said vehicle is provided on a junction between said front mount piece and said rear mount piece.