Selective internal distribution of engine motor oil

Abstract

Engine motor oil drawn from an oil sump by an oil pump is forced to flow through a primary flow path to moving engine parts at pressures spanning a first pressure range and a second pressure range which is greater than the first pressure range. When pressure is within the first pressure range, some engine motor oil flow may be diverted to a secondary flow path having piston cooling jets which spray engine motor oil toward undercrown surfaces of engine pistons. When pressure is within the second pressure range, some engine motor oil flow is diverted to the piston cooling jets and also to a tertiary flow path which may be a return to the oil sump.

What is claimed is: 
     
         1 . An internal combustion engine comprising:
 an oil sump for holding engine motor oil;   an oil pump for forcing engine motor oil drawn from the oil sump to flow under pressure through a primary flow path for delivering engine motor oil to moving parts of the engine including parts operatively associated with pistons which reciprocate within engine cylinders;   a pressure regulating mechanism comprising an inlet port which is open to the primary flow path at a location between the oil pump and the moving parts of the engine, a first outlet port, and a second outlet port,   the pressure regulating mechanism being responsive to a first range of oil pressure at the inlet port for controlling flow of engine motor oil from the primary flow path to the first outlet port while disallowing engine motor oil flow to the second outlet port,   the pressure regulating mechanism being responsive to a second range of oil pressure at the inlet port greater than the first range of oil pressure to provide for engine motor oil to flow from the primary flow path both to the first outlet port and to the second outlet port; and   a secondary flow path through which engine motor oil is delivered from the first outlet port to the pistons.   
     
     
         2 . The internal combustion engine as set forth in  claim 1  in which the secondary flow path comprises cooling jets through which engine motor oil is sprayed toward undercrown surfaces of the pistons. 
     
     
         3 . The internal combustion engine as set forth in  claim 1  comprising a tertiary flow path for engine motor oil to flow from the second outlet port. 
     
     
         4 . The internal combustion engine as set forth in  claim 1  in which the pressure regulating mechanism is contained within a housing which comprises a passage having an end open to the primary flow path, the pressure regulating mechanism comprising a plunger which is displaceable within the passage and is biased by a spring toward the end of the passage open to the primary flow path to seat on a seat surface of the housing in the absence of any oil pressure at the inlet port. 
     
     
         5 . The internal combustion engine as set forth in  claim 4  including a leak path for oil to flow from the primary flow path to the first outlet port when the plunger seats on the seat surface of the housing. 
     
     
         6 . The internal combustion engine as set forth in  claim 5  in which the leak path for oil to flow from the primary flow path to the first outlet port when the plunger seats on the seat surface of the housing is cooperatively defined between the plunger and the seat surface of the housing. 
     
     
         7 . An internal combustion engine comprising:
 an oil sump for holding engine motor oil;   an oil pump for forcing engine motor oil drawn from the oil sump to flow under pressure through a primary flow path for delivering engine motor oil to moving parts of the engine including parts operatively associated with pistons which reciprocate within engine cylinders;   a pressure regulating mechanism comprising an inlet port which is open to the primary flow path at a location between the oil pump and the moving parts of the engine, a first outlet port, and a second outlet port; and   a secondary flow path for engine motor oil to flow from the first outlet port to cooling jets which are arranged to spray engine motor oil toward undercrown surfaces of the pistons;   the pressure regulating mechanism being operative, as a function of oil pressure at the inlet port, to selectively control flow of engine motor oil from the primary flow path to the first outlet port and to the second outlet port.   
     
     
         8 . The internal combustion engine as set forth in  claim 7  in which the pressure regulating mechanism is operative, for a first range of oil pressure at the inlet port, to control flow of engine motor oil from the primary flow path to the first outlet port while disallowing engine motor oil flow to the second outlet port, and for a second range of oil pressure at the inlet port greater than the first range of oil pressure to provide a flow path for engine motor oil from the primary flow path both to the first outlet port and to the second outlet port. 
     
     
         9 . The internal combustion engine as set forth in  claim 7  comprising a tertiary flow path for engine motor oil to flow from the second outlet port. 
     
     
         10 . The internal combustion engine as set forth in  claim 7  in which the pressure regulating mechanism is contained within a housing which comprises a passage having an end open to the primary flow path, the pressure regulating mechanism comprising a plunger which is displaceable within the passage and is biased by a spring toward the end of the passage open to the primary flow path to seat on a seat surface of the housing in the absence of any oil pressure at the inlet port. 
     
     
         11 . The internal combustion engine as set forth in  claim 10  including a leak path for oil to flow from the primary flow path to the first outlet port when the plunger seats on the seat surface of the housing. 
     
     
         12 . The internal combustion engine as set forth in  claim 11  in which the leak path for oil to flow from the primary flow path to the first outlet port when the plunger seats on the seat surface of the housing is cooperatively defined between the plunger and the seat surface of the housing. 
     
     
         13 . A method of internally distributing engine motor oil within an internal combustion engine, the method comprising:
 forcing engine motor oil drawn by a pump from an oil sump to flow at oil pressures spanning a first pressure range and a second pressure range which is greater than the first pressure range through a primary flow path which delivers engine motor oil to moving parts of the engine, including parts operatively associated with pistons which reciprocate within engine cylinders;   selectively controlling, as a function of oil pressure in the primary flow path, flow of some engine motor oil from the primary flow path through a secondary flow path comprising cooling jets which are arranged to spray engine motor oil toward undercrown surfaces of the pistons and through a tertiary flow path such that when oil pressure in the primary flow path is within the first pressure range, engine motor oil flow through the secondary flow path is controlled and engine motor oil flow through the tertiary flow path is disallowed, and when oil pressure in the primary flow path is within the second pressure range, engine motor oil flows both through the secondary flow path and through the tertiary flow path.