Watercraft and exhaust structure of the watercraft

Abstract

An exhaust system for a watercraft with an engine includes an upstream exhaust pipe including an end portion with an outlet, a water lock including an inner space accommodating the end portion, a downstream exhaust pipe connected to the water lock, and a flow direction diverter, such as a baffle. The upstream exhaust pipe guides exhaust gas from the engine to the end portion. The inner space of the water lock receives the exhaust gas from the outlet of the end portion. The downstream exhaust pipe exhausts the exhaust gas from the inner space to an outside of the watercraft body. The flow direction diverter changes a flow direction of the exhaust gas at the outlet to a cross direction which intersects a pipe axis of the end portion.

What is claimed is: 
     
         1 . A watercraft comprising:
 a watercraft body;   an engine in the watercraft body;   an upstream exhaust pipe that includes an end portion with an outlet, and that guides exhaust gas from the engine to the end portion;   a water lock that includes an inner space which houses the end portion and into which the exhaust gas flows from the outlet;   a downstream exhaust pipe that is connected to the water lock, and that exhausts the exhaust gas from the inner space to an outside of the watercraft body; and   a flow direction diverter that changes a flow direction of the exhaust gas at the outlet to a cross direction which intersects a pipe axis of the end portion.   
     
     
         2 . The watercraft according to  claim 1 , wherein the end portion penetrates an inner wall of the water lock, and the flow direction diverter changes the flow direction of the exhaust gas to a direction along the inner wall. 
     
     
         3 . The watercraft according to  claim 1 , wherein the outlet opens radially to an outside of the upstream exhaust pipe at the end portion. 
     
     
         4 . The watercraft according to  claim 1 , wherein the flow direction diverter includes a baffle that blocks the exhaust gas which reaches the end portion to change the flow direction of the exhaust gas. 
     
     
         5 . The watercraft according to  claim 4 , further comprising a fastener that fastens the baffle to the end portion. 
     
     
         6 . The watercraft according to  claim 5 , wherein the fastener includes three or more fasteners. 
     
     
         7 . The watercraft according to  claim 1 , further comprising a drain pipe that surrounds the end portion; wherein
 a flow passage defined between the drain pipe and the end portion guides engine cooling water to the inner space.   
     
     
         8 . An exhaust system for a watercraft with an engine, the exhaust system comprising:
 an upstream exhaust pipe that includes an end portion with an outlet, and that guides exhaust gas from the engine to the end portion;   a water lock that includes an inner space which houses the end portion and into which the exhaust gas flows from the outlet;   a downstream exhaust pipe that is connected to the water lock, and that exhausts the exhaust gas from the inner space to an outside of the watercraft body; and   a flow direction diverter that changes a flow direction of the exhaust gas at the outlet to a cross direction which intersects a pipe axis of the end portion.   
     
     
         9 . The exhaust system for a watercraft according to  claim 8 , wherein the end portion penetrates an inner wall of the water lock, and the flow direction diverter changes the flow direction of the exhaust gas to a direction along the inner wall. 
     
     
         10 . The exhaust system for a watercraft according to  claim 8 , wherein the outlet opens radially to an outside of the upstream exhaust pipe at the end portion. 
     
     
         11 . The exhaust system for a watercraft according to  claim 8 , wherein the flow direction diverter includes a baffle that blocks the exhaust gas which reaches the end portion to change the flow direction of the exhaust gas. 
     
     
         12 . The exhaust system for a watercraft according to  claim 11 , further comprising a fastener that fastens the baffle to the end portion. 
     
     
         13 . The exhaust system for a watercraft according to  claim 12 , wherein the fastener includes three or more fasteners. 
     
     
         14 . The exhaust system for a watercraft according to  claim 8 , further comprising a drain pipe that surrounds the end portion; wherein
 a flow passage defined between the drain pipe and the end portion guides engine cooling water to the inner space.