Muffler for small-sized vehicle

1. A muffler for an internal combustion engine, said muffler comprising:

a muffler main body, said muffler main body comprising an outer plate configured in a shape of a cylinder, wherein an inside of the muffler main body comprises a plurality of expansion chambers in communication with each other, said expansion chambers being separated by partition walls attached to an inner peripheral surface of the outer plate;

a catalyst disposed in an upstream-side expansion chamber, said upstream-side expansion chamber being configured to be connected to a downstream side of an exhaust pipe;

an exhaust gas discharging port disposed at a downstream end of a downstream-side expansion chamber; and

a cylinder-shaped reinforcement member attached to the inner peripheral surface of the outer plate, said cylinder-shaped reinforcement member being independent of the partition walls, and disposed inside of the upstream-side expansion chamber.

2. The muffler according to claim 1 , wherein a volume of the upstream-side expansion chamber containing the catalyst is larger than a volume of each of a plurality of downstream-side expansion chambers.

3. The muffler according to claim 2 , wherein a plane of projection of an outlet of the catalyst in an axial direction intersects a line parallel to a center axis line of the muffler main body, and wherein an outlet of the catalyst is directed to a join portion where a first partition wall defining the upstream-side expansion chamber and the outer plate are joined together.

4. The muffler according to claim 3 , wherein the outlet of the catalyst is configured to be directed upward when the muffler is installed on a vehicle, and wherein a face-to-face weld portion of the cylinder-shaped reinforcement member is provided at what is configured to be a side portion of the muffler main body in a left-right direction when the muffler main body is installed on the vehicle.

5. The muffler according to claim 1 , wherein the cylinder-shaped outer plate of the muffler main body includes a plurality of through-holes corresponding to attachment points of the cylinder-shaped reinforcement member, and wherein the through-holes are occluded by the cylinder-shaped reinforcement member.

6. The muffler according to claim 1 , wherein the cylinder-shaped reinforcement member and the outer plate of the muffler main body comprise a common steel plate, and wherein a plate thickness of the cylinder-shaped reinforcement member is thicker than a plate thickness of the outer plate of the muffler main body.

7. The muffler according to claim 5 , wherein the outer plate of the muffler main body includes weld holes therein, and wherein the through-holes in the muffler main body are a same size as the weld holes, and wherein the weld holes are in a location which corresponds to a location of the partition walls.

8. A vehicle comprising a muffler according to claim 1 .

9. A vehicle comprising a muffler according to claim 2 .

10. A vehicle comprising a muffler according to claim 3 .

11. A vehicle comprising a muffler according to claim 4 .

12. A vehicle comprising a muffler according to claim 5 .

13. A vehicle comprising a muffler according to claim 6 .

14. A vehicle comprising a muffler according to claim 7 .

15. A muffler for an internal combustion engine, said muffler comprising:

main body means for forming a main body of the muffler, said main body means comprising an outer portion configured in a shape of a cylinder, wherein an inside of the main body means comprises a plurality of expansion chambers in communication with each other, said expansion chambers being separated by a plurality of partition means for partitioning the inside of the main body means;

catalyst means for catalyzing exhaust gases, said catalyst means being disposed in an upstream-side expansion chamber, said upstream-side expansion chamber being connected to a downstream side of an exhaust pipe;

discharging means for discharging exhaust gases, said discharging means disposed at a downstream end of a downstream-side expansion chamber; and

reinforcement means attached to an inner peripheral surface of the outer portion, said reinforcement means being independent of the partition means, and disposed inside of the upstream-side expansion chamber.

16. A muffler for an internal combustion engine, said muffler comprising:

main body means for forming a main body of the muffler, said main body means comprising an outer portion configured in a shape of a cylinder, wherein an inside of the main body means comprises a plurality of expansion chambers in communication with each other, said expansion chambers being separated by a plurality of partition means for partitioning the inside of the main body means;

catalyst means for catalyzing exhaust gases, said catalyst means being disposed in an upstream-side expansion chamber, said upstream-side expansion chamber being connected to a downstream side of an exhaust pipe;

discharging means for discharging exhaust gases, said discharging means disposed at a downstream end of a downstream-side expansion chamber; and

reinforcement means attached to an inner peripheral surface of the outer portion, said reinforcement means being independent of the partition means, and disposed inside of the upstream-side expansion chamber,

wherein a volume of the upstream-side expansion chamber containing the catalyst means is larger than a volume of each of a plurality of downstream-side expansion chambers.

17. The muffler according to claim 16 , wherein a plane of projection of an outlet of the catalyst means in an axial direction intersects a line parallel to a center axis of the main body means, and wherein an outlet of the catalyst means is directed to a join portion where a first partition means defining the upstream-side expansion chamber and the outer portion are joined together.

18. The muffler according to claim 17 , wherein the outlet of the catalyst means is directed upward when the muffler is installed on a vehicle, and wherein a face-to-face weld portion of the reinforcement means is provided at a side portion of the main body means in a left-right direction when the main body means is installed on the vehicle.

19. A muffler for an internal combustion engine, said muffler comprising:

main body means for forming a main body of the muffler, said main body means comprising an outer portion configured in a shape of a cylinder, wherein an inside of the main body means comprises a plurality of expansion chambers in communication with each other, said expansion chambers being separated by a plurality of partition means for partitioning the inside of the main body means;

catalyst means for catalyzing exhaust gases, said catalyst means being disposed in an upstream-side expansion chamber, said upstream-side expansion chamber being connected to a downstream side of an exhaust pipe;

discharging means for discharging exhaust gases, said discharging means disposed at a downstream end of a downstream-side expansion chamber; and

reinforcement means attached to an inner peripheral surface of the outer portion, said reinforcement means being independent of the partition means, and disposed inside of the upstream-side expansion chamber,

wherein the outer portion of the main body means includes a plurality of through-holes corresponding to attachment points of the reinforcement means, and wherein the through-holes are occluded by the reinforcement means.

20. The muffler according to claim 15 , wherein the reinforcement means and the outer portion of the main body means comprise a common steel plate, and wherein a plate thickness of the reinforcement means is thicker than a plate thickness of the outer portion of the main body means.

21. The muffler according to claim 19 , wherein the outer portion of the main body means includes weld holes therein, and wherein the through-holes in the main body means are a same size as the weld holes, and wherein the weld holes are in a location which corresponds to a location of the partition means.