Lubricant supply system for an engine

Abstract

A lubricant supply system for an engine includes an oil pump activated by an engine having a crank system and a valve system, a main passage connected to the oil pump for supplying a lubricant to the engine, a crank system passage branched from the main passage for supplying the lubricant to the crank system, a valve system passage branched from the main passage for supplying the lubricant to the valve system, an oil pressure relief valve disposed in the crank system passage, and an oil pressure detecting type orifice valve disposed in the valve system passage.

What we claim is:  
     
         1 . A lubricant supply system for an engine comprising: 
 an oil pump activated by an engine having a crank system and a valve system;    a main passage connected to the oil pump for supplying a lubricant to the engine;    a crank system passage branched from the main passage for supplying the lubricant to the crank system;    a valve system passage branched from the main passage for supplying the lubricant to the valve system;    an oil pressure relief valve disposed in the crank system passage; and    an oil pressure detecting type orifice valve disposed in the valve system passage.    
     
     
         2 . A lubricant supply system for an engine according to  claim 1 , wherein the oil pressure relief valve reduces an oil pressure in the crank system passage to be less than a predetermined oil pressure when the oil pressure in the crank system passage becomes substantially equal to or greater than the predetermined oil pressure.  
     
     
         3 . A lubricant supply system for an engine according to  claim 2 , wherein the predetermined oil pressure is preset to be greater than an oil pressure required by the crank system.  
     
     
         4 . A lubricant supply system for an engine according to  claim 3 , wherein the oil pressure detecting type orifice valve increases passage resistance of the valve system passage in response to increase of an inner pressure of the valve system passage, wherein the lubricant is restrained from being excessively supplied to the valve system.  
     
     
         5 . A lubricant supply system for an engine according to  claim 2 , wherein the oil pressure relief valve is an oil pressure detecting means.  
     
     
         6 . A lubricant supply system for an engine according to  claim 5 , wherein the oil pressure detecting means includes an oil pressure receiving portion, an oil pressure shut-off valve, and an oil pressure relief spring, and the oil pressure relief spring is compressed when the oil pressure in the crank system passage becomes substantially equal to or greater than the predetermined oil pressure.  
     
     
         7 . A lubricant supply system for an engine according to  claim 6 , wherein a set load of the oil pressure relief spring is a constant value.  
     
     
         8 . A lubricant supply system for an engine according to  claim 6 , wherein a set load of the oil pressure relief spring is a variable value.