Marine vessel and marine engine cooling system

Abstract

A marine vessel includes a cooling flow passage to allow cooling water to flow into a cylinder block from a lower side of the cylinder block via a lower end flow passage port in a vicinity of or adjacent to a lower end of a flow passage portion in the cylinder block.

What is claimed is: 
     
         1 . A marine vessel comprising:
 a hull;   an engine in the hull and including an exhaust manifold, a cylinder head, and a cylinder block;   a cooling flow passage to allow cooling water to flow therethrough to cool the engine; and   a thermostat in a vicinity of or adjacent to a cooling water outlet of the cylinder block to adjust a flow rate of the cooling water discharged from the cylinder block based on a temperature of the cooling water; wherein   the cooling flow passage is operable to allow the cooling water that has flowed through the exhaust manifold to flow into the cylinder block via the cylinder head and to allow the cooling water to flow into the cylinder block from a lower side of the cylinder block via a lower end flow passage port in a vicinity of or adjacent to a lower end of a flow passage portion in the cylinder block.   
     
     
         2 . The marine vessel according to  claim 1 , wherein
 the engine includes an oil cooler; and   the cooling flow passage is operable to allow the cooling water that has flowed through the oil cooler to flow into the cylinder block from the lower side via the lower end flow passage port.   
     
     
         3 . The marine vessel according to  claim 1 , wherein the cooling flow passage is operable to allow the cooling water that has flowed through the cylinder head to be discharged to an outside of the cylinder head via an upper end flow passage port in a vicinity of or adjacent to an upper end of a flow passage portion in the cylinder head. 
     
     
         4 . The marine vessel according to  claim 3 , further comprising:
 a rectifier/regulator to control the engine; wherein   the cooling flow passage is operable to allow the cooling water discharged to the outside of the cylinder head via the upper end flow passage port to be discharged to an outside of the hull via the rectifier/regulator.   
     
     
         5 . The marine vessel according to  claim 3 , wherein the cooling flow passage is operable to allow a portion of the cooling water that has flowed through the cylinder head to flow into the cylinder block, and allow a remaining portion of the cooling water that has flowed through the cylinder head to be discharged to the outside of the cylinder head via the upper end flow passage port. 
     
     
         6 . The marine vessel according to  claim 1 , wherein the cooling flow passage includes a flow passage connecting the cylinder head to the cylinder block that has a cross-sectional area smaller than a cross-sectional area of a flow passage connecting the exhaust manifold to the cylinder head. 
     
     
         7 . The marine vessel according to  claim 3 , wherein the cooling flow passage includes a flow passage connected to the cylinder head via the upper end flow passage port that has a cross-sectional area smaller than a cross-sectional area of a flow passage connecting the exhaust manifold to the cylinder head. 
     
     
         8 . The marine vessel according to  claim 3 , wherein the cooling flow passage includes a flow passage connected to the cylinder head via the upper end flow passage port that has a cross-sectional area smaller than a cross-sectional area of a flow passage connecting the cylinder head to the cylinder block. 
     
     
         9 . The marine vessel according to  claim 1 , wherein the cooling flow passage includes a flow passage connected to the cylinder block via the lower end flow passage port that has a cross-sectional area smaller than a cross-sectional area of a flow passage connecting the cylinder head to the cylinder block. 
     
     
         10 . The marine vessel according to  claim 2 , wherein the cooling flow passage is operable to allow a portion of the cooling water that has flowed in from outside the hull to flow into the exhaust manifold, and allow a remaining portion of the cooling water that has flowed in from outside the hull to flow into the oil cooler. 
     
     
         11 . The marine vessel according to  claim 1 , wherein the thermostat is operable to adjust the flow rate of the cooling water discharged from the cylinder block such that the temperature of the cooling water becomes a predetermined temperature of about 50 degrees or more and about 70 degrees or less. 
     
     
         12 . The marine vessel according to  claim 1 , wherein the cooling flow passage is operable to allow all of the cooling water that has flowed through the exhaust manifold to flow into the cylinder head. 
     
     
         13 . The marine vessel according to  claim 1 , further comprising:
 a jet propulsion thruster to generate a thrust using a driving force of the engine.   
     
     
         14 . A marine engine cooling system comprising:
 a cooling flow passage to allow cooling water to flow therethrough to cool an engine in a hull including an exhaust manifold, a cylinder head, and a cylinder block, and to allow the cooling water that has flowed through the exhaust manifold to flow into the cylinder block via the cylinder head; and   a thermostat in a vicinity of or adjacent to a cooling water outlet of the cylinder block to adjust a flow rate of the cooling water discharged from the cylinder block based on a temperature of the cooling water; wherein   the cooling flow passage is operable to allow the cooling water to flow into the cylinder block from a lower side of the cylinder block via a lower end flow passage port in a vicinity of or adjacent to a lower end of a flow passage portion in the cylinder block.   
     
     
         15 . The marine engine cooling system according to  claim 14 , wherein the engine includes an oil cooler, and the cooling flow passage is operable to allow the cooling water that has flowed through the oil cooler to flow into the cylinder block from the lower side via the lower end flow passage port. 
     
     
         16 . The marine engine cooling system according to  claim 14 , wherein the cooling flow passage is operable to allow the cooling water that has flowed through the cylinder head to be discharged to an outside of the cylinder head via an upper end flow passage port in a vicinity of or adjacent to an upper end of a flow passage portion in the cylinder head. 
     
     
         17 . The marine engine cooling system according to  claim 16 , wherein the hull includes a rectifier/regulator used to control the engine, and the cooling flow passage is operable to allow the cooling water discharged to the outside of the cylinder head via the upper end flow passage port to be discharged to an outside of the hull via the rectifier/regulator. 
     
     
         18 . The marine engine cooling system according to  claim 16 , wherein the cooling flow passage is operable to allow a portion of the cooling water that has flowed through the cylinder head to flow into the cylinder block, and allow a remaining portion of the cooling water that has flowed through the cylinder head to be discharged to the outside of the cylinder head via the upper end flow passage port. 
     
     
         19 . The marine engine cooling system according to  claim 14 , wherein the cooling flow passage includes a flow passage connecting the cylinder head to the cylinder block that has a cross-sectional area smaller than a cross-sectional area of a flow passage connecting the exhaust manifold to the cylinder head. 
     
     
         20 . The marine engine cooling system according to  claim 16 , wherein the cooling flow passage includes a flow passage connected to the cylinder head via the upper end flow passage port that has a cross-sectional area smaller than a cross-sectional area of a flow passage connecting the exhaust manifold to the cylinder head.