Oil supply device for engine

Abstract

An oil supply device for an engine includes a first oil suction passage, a second oil suction passage, a first pump for sucking and discharging oil from the first oil suction passage, a second pump arranged in series with the first pump, the second pump for sucking and discharging oil from at least one of the first pump and the second oil suction passage, a check valve for blocking oil circulation, a first oil passage, a second oil passage, a third oil passage for establishing communication between the first oil passage and the second oil passage, and a supply volume control device for varying oil supply volume to a lubrication system portion, to a cooling system portion, or to the lubrication system portion and the cooling system portion in accordance with a change in at least one of an engine oil temperature, an engine rotation speed, and an engine load.

1 . An oil supply device for an engine for supplying oil to a lubrication system portion and a cooling system portion of an engine, comprising: 
 a first oil suction passage in communication with an oil reservoir which reserves oil;    a second oil suction passage in communication with the oil reservoir;    a first pump for sucking oil from the first oil suction passage by means of rotation of crankshaft of the engine and for discharging the sucked oil;    a second pump arranged in series with the first pump for controlling switching On-Off operation, the second pump configured to be supplied with oil discharged from the first pump and introduced from the second oil suction passage for sucking and discharging oil from at least one of the first pump and the second oil suction passage;    a check valve for blocking oil circulation from the second pump to the first pump and from the second oil suction passage to the first pump;    a first oil passage diverged between the check valve and the first pump and extended to the lubrication system portion;    a second oil passage extended from the second pump to the cooling system portion;    a third oil passage for establishing communication between the first oil passage and the second oil passage; and    a supply volume control means for varying oil supply volume to the lubrication system portion, to the cooling system portion, or to the lubrication system portion and the cooling system portion in accordance with a change in at least one of an engine oil temperature, an engine rotation speed, and an engine load.    
     
     
         2 . The oil supply device according to  claim 1 , wherein the supply volume control means varies the oil supply volume to the lubrication system portion, to the cooling system portion, or to the lubrication system portion and the cooling system portion by controlling switching On-Off operation of the second pump.  
     
     
         3 . The oil supply device according to  claim 2 , further comprising: 
 a first valve provided on the third oil passage for blocking oil circulation from the first oil passage to the second oil passage.    
     
     
         4 . The oil supply device according to  claim 2 , further comprising: 
 a second valve provided on the first oil passage at upstream side relative to a connection point between the first oil passage and the third oil passage.    
     
     
         5 . The oil supply device according to  claim 4 , wherein the second valve is a check valve for allowing oil circulation only in a direction from the first pump to the lubrication system portion.  
     
     
         6 . The oil supply device according to  claim 4 , wherein the second valve is an opening and closing valve for blocking oil circulation in the first oil passage.  
     
     
         7 . The oil supply device according to  claim 4 , further comprising: 
 a third valve provided on the first oil passage at downstream side relative to the connection point between the first oil passage and the third oil passage.    
     
     
         8 . The oil supply device according to  claim 7 , wherein the third valve is opened at a predetermined pressure.  
     
     
         9 . The oil supply device according to  claim 7 , further comprising: 
 a fourth valve provided on the second oil passage at downstream side relative to a connection point between the second oil passage and the third oil passage.    
     
     
         10 . The oil supply device according to  claim 9 , wherein the fourth valve is a flow adjusting valve for adjusting volume of flown oil.  
     
     
         11 . The oil supply device according to  claim 9 , wherein the supply volume control means controls an opening degree of the fourth valve and opening and closing of the second and the third valves.  
     
     
         12 . The oil supply device according to  claim 9 , wherein the supply volume control means controls an opening degree of the fourth valve and opening and closing of the third valve.  
     
     
         13 . The oil supply device according to  claim 9 , wherein the supply volume control means controls an opening degree of the fourth valve.  
     
     
         14 . The oil supply device according to  claim 2 , further comprising: 
 a third valve provided on the first oil passage at downstream side relative to a connection point between the first oil passage and the third oil passage.    
     
     
         15 . The oil supply device according to  claim 14 , wherein the third valve is opened at a predetermined pressure.  
     
     
         16 . The oil supply device according to  claim 14 , further comprising: 
 a fourth valve provided on the second oil passage at downstream side relative to a connection point between the second oil passage and the third oil passage.    
     
     
         17 . The oil supply device according to  claim 16 , wherein the fourth valve is a flow volume-adjusting valve for adjusting volume of flown oil.  
     
     
         18 . The oil supply device according to  claim 16 , wherein the supply volume control means controls opening and closing of the third valve and the fourth valve.  
     
     
         19 . The oil supply device according to  claim 2 , further comprising a fourth valve provided on the second oil passage at downstream side relative to a connection point between the second oil passage and the third oil passage.  
     
     
         20 . The oil supply device according to  claim 19 , wherein the fourth valve is a flow volume adjusting valve for adjusting volume of flown oil.