Relief device for oil circuit of engine

Abstract

A relief device including: an oil pump; an upstream flow passage provided from a discharge section side of the oil pump to an engine; an oil-pressure relief valve relieving oil by a valve body moving due to oil pressure; and a temperature-sensitive relief valve B relieving oil by detecting an oil temperature and opening and closing steplessly. The oil-pressure relief valve and the temperature-sensitive relief valve are disposed in parallel in the upstream flow passage. A portion of the pump housing of the oil pump is formed in an integrated fashion with a casing of an oil circulation mechanism. An oil filter 102 is provided in the upstream flow passage 61 , and the temperature-sensitive relief valve B is positioned on the upstream side of the oil filter.

1 . A relief device for an oil circuit of an engine,
 the device comprising:   an oil pump;   an upstream flow passage provided from a discharge section side of the oil pump to an engine;   an oil-pressure relief valve which relieves oil by a valve body moving due to oil pressure; and   a temperature-sensitive relief valve which relieves oil by detecting an oil temperature and opening and closing steplessly, wherein   the oil-pressure relief valve and the temperature-sensitive relief valve are disposed in parallel arrangement in the upstream flow passage,   an oil filter is provided in the upstream flow passage, and   the temperature-sensitive relief valve is positioned on the upstream side of the oil filter.   
     
     
         2 . The relief device for an oil circuit of an engine according to  claim 1 , wherein, when the oil temperature is low, the temperature-sensitive relief valve relieves oil. 
     
     
         3 . The relief device for an oil circuit of an engine according to  claim 1 , wherein, when the oil temperature is medium, the amount of oil relieved by the temperature-sensitive relief valve becomes greater near a low oil temperature, and becomes smaller near a high oil temperature. 
     
     
         4 . The relief device for an oil circuit of an engine according to  claim 1 , wherein, when the oil temperature is high, the temperature-sensitive relief valve does not relieve oil. 
     
     
         5 . The relief device for an oil circuit of an engine according to  claim 1 , wherein the temperature-sensitive relief valve is provided in the engine. 
     
     
         6 . The relief device for an oil circuit of an engine according to  claim 1 , wherein
 a relief flow passage branches from the upstream flow passage,   the oil-pressure relief valve and the temperature-sensitive relief valve are provided in a parallel arrangement in the relief flow passage, and   the branch section of the relief flow passage is positioned on the upstream side of the oil filter.