Muffler for engine

Abstract

A muffler for an engine is provided. A muffler ( 50 ) according to an embodiment of the present invention includes a box-shaped housing ( 51 ), and a partition ( 56 ) that divides the inside of the housing ( 51 ) into a first chamber ( 61 ) and a second chamber ( 62 ). The partition ( 56 ) includes a main body portion ( 56 a ) in the form of a flat plate, and a concave portion ( 56 b ) that protrudes toward the second chamber ( 62 ). Exhaust gas, having flowed from an inlet ( 52 a ) of the housing ( 51 ) into the first chamber ( 61 ), passed a through hole ( 57 ) of the main body portion ( 56 a ), and reached one side in the second chamber ( 62 ), flows inside the second chamber ( 62 ) so as to bypass a second concave portion ( 56 b 2 ) of the concave portion ( 56 b ) and then passes the other side in the second chamber ( 62 ) to reach an outlet ( 53 a ) of the housing ( 51 ).

What is claimed is: 
     
         1 . A muffler for an engine, comprising:
 a box-shaped housing having an inlet that is connected with an exhaust port of the engine to allow exhaust gas to flow in, and an outlet for discharging the exhaust gas having flowed in; and   a partition for dividing the inside of the housing into a first chamber with the inlet and a second chamber with the outlet,   wherein the partition includes a main body portion in the form of a flat plate, and a concave portion that protrudes toward the second chamber from the main body portion,   the main body portion has, on one side thereof, at least one through hole that communicates between the first and second chambers,   at least a portion of the bottom of the concave portion contacts an inner surface of the second chamber in the housing, and   exhaust gas having flowed from the inlet into the first chamber, passed the through hole, and reached one side in the second chamber, flows inside the second chamber so as to bypass the concave portion and then passes the other side in the second chamber to reach the outlet.   
     
     
         2 . The muffler for an engine according to  claim 1 , wherein the concave portion is positioned between the outlet and the through hole. 
     
     
         3 . The muffler for an engine according to  claim 1 , wherein the concave portion faces the inlet. 
     
     
         4 . The muffler for an engine according to  claim 3 ,
 wherein the inlet is formed at an upper portion of the first chamber, and   the concave portion receives exhaust gas having flowed from the inlet into the first chamber and guides the gas downward.   
     
     
         5 . The muffler for an engine according to  claim 1 ,
 wherein the main body portion has the through hole on one horizontal side thereof, and   exhaust gas having flowed from the inlet into the first chamber, passed the through hole, and reached one horizontal side in the second chamber, flows inside the second chamber so as to pass above and/or below the concave portion and then passes the other horizontal side in the second chamber to reach the outlet.   
     
     
         6 . The muffler for an engine according to  claim 1 ,
 wherein the housing includes a convex portion that protrudes outward so as to cover the outlet, and the convex portion has an opening, and   a tubular exhaust gas passage for guiding exhaust gas from the outlet to the opening is defined by the convex portion and a portion of the bottom of the concave portion, which partially blocks the outlet.   
     
     
         7 . A muffler for an engine, comprising:
 a box-shaped housing having an inlet that is connected with an exhaust port of the engine to allow exhaust gas to flow in, and an outlet for discharging the exhaust gas having flowed in;   a partition for dividing the inside of the housing into a first chamber with the inlet and a second chamber with the outlet; and   a flow regulating part for partially regulating the flow of exhaust gas inside the second chamber,   wherein the partition has, on one side thereof, at least one through hole that communicates between the first and second chambers, and   exhaust gas having flowed from the inlet into the first chamber, passed the through hole, and reached one side in the second chamber, flows inside the second chamber so as to bypass the flow regulating part and then passes the other side in the second chamber to reach the outlet.   
     
     
         8 . The muffler for an engine according to  claim 7 , wherein the flow regulating part is positioned between the outlet and the through hole. 
     
     
         9 . The muffler for an engine according to  claim 7 ,
 wherein the partition has, on one horizontal side thereof, the through hole, and   exhaust gas having flowed from the inlet into the first chamber, passed the through hole, and reached one horizontal side in the second chamber, flows inside the second chamber so as to pass above and/or below the flow regulating part and then passes the other horizontal side in the second chamber to reach the outlet.   
     
     
         10 . The muffler for an engine according to  claim 7 , wherein the flow regulating part constitutes a portion of the partition or a portion of the housing. 
     
     
         11 . The muffler for an engine according to  claim 7 , wherein the flow regulating part is positioned inside the second chamber, between the housing and the partition.