초록 ▼

A powerboat muffler is disclosed that balances decreasing exhaust noise and producing power. A muffler cannister has concentric inlet tubes, forming an inlet baffle, where exhaust gas and engine coolant enters the muffler, a V-shaped baffle within the cannister, a funneled outlet, and concentric out

A powerboat muffler is disclosed that balances decreasing exhaust noise and producing power. A muffler cannister has concentric inlet tubes, forming an inlet baffle, where exhaust gas and engine coolant enters the muffler, a V-shaped baffle within the cannister, a funneled outlet, and concentric outlet tubes, forming an outlet baffle. The inlet baffle comprises concentric outer and inner tubes and the front wall of the muffler, which together form an toroidal inlet space. The inner inlet tube extends a certain distance into the muffler cannister. The inside wall of the inner inlet tube is shaped to create a venturi. Through the front wall, within the toroidal inlet space, small venturi-shaped openings are disposed radially between the outer and inner tubes to allow engine exhaust and coolant to enter the muffler. At the outlet end of the muffler, a tapered nozzle funnels exhaust to an outlet tube with a venturi contour. The outlet tube extends out from the outlet nozzle a certain distance. Surrounding and concentric with the outlet tube is an outer outlet tube. The outer outlet tube, the inner outlet tube and the outside surface of the outlet nozzle form another toroidal baffling space at the tail end of the muffler.

대표청구항 ▼

1. A muffler for a powerboat engine comprising: a muffler housing having a side wall, an inlet end, an outlet end, a front wall at the inlet end, an outlet wall at the outlet end, and an interior space defined by the side wall, front wall and outlet wall, wherein the front wall has an exhaust inlet

1. A muffler for a powerboat engine comprising: a muffler housing having a side wall, an inlet end, an outlet end, a front wall at the inlet end, an outlet wall at the outlet end, and an interior space defined by the side wall, front wall and outlet wall, wherein the front wall has an exhaust inlet opening and the outlet wall has an exhaust outlet opening,an outer inlet tube joined to the front wall and extending from the front wall in a direction away from the outlet end of the muffler housing, wherein the outer inlet tube is sized for connection to an exhaust pipe and further has an outer inlet tube cross section area,an inner inlet tube having an engine exhaust pipe end, a muffler end, an inner inlet tube length between the engine exhaust pipe end and the muffler end, an inner inlet tube outside surface along the inlet inner tube length, an inner inlet tube inside surface along the inner inlet tube length, and an inner inlet tube cross section area smaller than the outer inlet tube cross section area, wherein the exhaust inlet opening of the front wall is sized for the inner inlet tube cross section to receive the inner inlet tube length, and wherein a muffler portion of the inner inlet tube length extends from the front wall into the interior space of the muffler housing, and wherein an exhaust portion of the inner inlet tube length extends from the front wall into the outer inlet tube,an inlet space formed between the outer inlet tube, the inner inlet tube outside surface at the exhaust pipe portion of the inner inlet tube, and a front wall portion between the outer inlet tube and inner inlet tube outside surface, wherein the front wall portion further comprises a plurality of front wall apertures between the inlet space and the interior space of the muffler housing,a baffle arranged in the interior space between the front wall and the outlet wall, andan outlet tube having an outlet tube muffler end, an outlet tube tail end opposite the outlet tube muffler end, and an outlet tube cross section at the outlet tube muffler end, wherein the exhaust outlet opening of the outlet wall is sized for the outlet tube. 2. The muffler of claim 1 wherein the inner inlet tube inside surface forms a venturi along the inner inlet tube length. 3. The muffler of claim 2 wherein the plurality of front wall apertures form venturis between the inlet space and the interior space of the muffler housing. 4. The muffler of claim 3 further comprising: an outer outlet tube joined to the outlet wall and extending from the outlet wall in a direction opposite the inlet end of the muffler housing, wherein the outer outlet tube has an outer outlet tube cross section area,wherein the outlet tube further comprises an outlet tube length and an outlet tube inside surface along the outlet tube length, wherein the outlet tube cross section area is smaller than the outer outlet tube cross section area, and wherein an exhaust portion of the outlet tube length extends from the exhaust outlet wall in the direction opposite the inlet end of the muffler housing, andan outlet space formed between the outer outlet tube, the outlet tube, and an outlet wall portion between the outer outlet tube and the outlet tube. 5. The muffler of claim 4 wherein the outlet wall forms a cone having a cone base joined to the outlet end of the muffler housing and narrowing to the exhaust outlet opening. 6. The muffler of claim 5 wherein the outlet tube cross section is smaller than a cross section of the outlet tube tail end. 7. The muffler of claim 6 wherein the baffle is V-shaped with a baffle tip and sides projecting down and outwardly from the baffle tip to bottom edges, wherein the baffle tip is directed toward the exhaust inlet opening and the baffle sides extend from the tip in a direction toward the exhaust outlet opening, wherein the baffle tip has a baffle width substantially equivalent to a housing width of the interior space of the muffler housing, and wherein a baffle outlet slit is formed between the bottom edges of the baffle sides and the side walls of the muffler housing. 8. The muffler of claim 7 wherein the sides of the V-shaped baffle have side edges extending from the tip to the bottom edge of each side, and wherein side edge portions of the side edges are fixed to the side walls of the muffler housing, and wherein at least one side edge has a side edge gap between the side edge and the side wall of the muffler housing. 9. The muffler of claim 7 wherein the bottom edges of the baffle sides further comprise baffle ends bent inwardly at an angle. 10. The muffler of claim 7 wherein the baffle sides form convexly bowed baffle surfaces. 11. The muffler of claim 1 wherein the engine exhaust pipe end of the inner inlet tube further comprises a plurality of passages allowing communication of exhaust between the inlet space and an inner inlet tube throat within the inner inlet tube inside surface along the inner inlet tube length. 12. An engine muffler comprising: a cannister having an inlet wall at a proximal end of the cannister, an outlet funnel at a distal end of the cannister, a substantially cylindrical side wall between the proximal and distal ends, an interior volume formed within the side wall between the proximal and distal ends, an inlet opening in the inlet wall for admission of exhaust from an engine, an exhaust pipe flange on the inlet wall surrounding the inlet opening and extending from the inlet wall to join with an exhaust pipe from the engine, an outlet opening at a narrow stem of the outlet funnel to discharge exhaust from the interior volume, and a tail pipe flange on a tapered side of the outlet funnel and extending away from the interior volume,an inlet tube extending through the inlet opening, the inlet tube having a inlet tube length, an inner contour, a pipe portion, a mid portion, and a cannister portion, wherein the inlet tube is joined to the inlet opening proximate to the mid portion, the pipe portion extends away from the inlet wall into the exhaust pipe flange, and the cannister portion extends from the inlet wall into the interior volume of the cannister, and wherein a mid-portion diameter at the mid portion is less than a pipe-portion diameter at the pipe portion and the mid-portion diameter is less than a cannister-portion diameter at the cannister portion,an inlet toroidal baffle area formed between the exhaust pipe flange, inlet wall, and pipe portion of the inlet tube, and wherein the inlet toroidal baffle area further comprises inlet venturis in the inlet wall to allow communication of exhaust between the inlet toroidal baffle area and the interior volume of the cannister,an outlet tube having a muffler end, a tail end, and an outlet tube length from the muffler end to the tail end, wherein the muffler end is joined to the outlet opening and the tail end extends away from the outlet opening away from the interior volume of the cannister, and wherein a muffler-end diameter at the muffler end of the outlet tube is less than a tail-end diameter at the tail end of the outlet tube, andan outlet toroidal baffle area formed between the tail pipe flange, tapered side of the outlet funnel, and outlet tube. 13. The engine muffler of claim 12 wherein the side wall between the proximal and distal ends of the cannister has a cannister length, the cannister portion of the inlet tube has a cannister portion length, and a ratio of the cannister length to the cannister portion length is between 11:1 and 7:1. 14. The muffler of claim 13 wherein the pipe portion of the inlet tube further comprises a plurality of pipe portion passages disposed radially at an angle normal to the inlet tube length. 15. The muffler of claim 12 further comprising a V-shaped baffle having a leading edge and a pair of trailing walls extending at a baffle angle from the leading edge to outlet ends, wherein the V-shaped baffle is disposed within the interior volume of the cannister and oriented so that the leading edge is proximate to the cannister portion of the inlet tube and the outlet ends are proximate to the outlet funnel, and wherein a baffle exhaust passage is formed between the outlet ends and the side wall of the cannister. 16. The muffler of claim 15 wherein the trailing walls of the V-shaped baffle have wall edges extending from the leading edge to the outlet ends, and wherein at least one wall edge has a gap between the wall edge and the side wall of the cannister. 17. The muffler of claim 16 wherein the outlet ends of the trailing walls further comprise baffle flaps bent inwardly. 18. The muffler of claim 15 wherein the trailing walls have wall surfaces curved outwardly toward the side wall of the cannister.