LUBRICANT VISCOSITY ADJUSTING DEVICE

PROBLEM TO BE SOLVED: To provide a lubricant viscosity adjusting device of an engine which can make compatible the improvement of fuel economy and durability reliability.SOLUTION: A lubricant viscosity adjusting device comprises: an oil pan 21 in which a lubricant of an engine 20 is stored; a first passage 11 in which supply means 14 for supplying fuel to the oil pan 21 from a fuel tank 10 is interposed; a second passage 12 for returning the fuel which is vaporized from the lubricant in the oil pan 21 to the fuel tank 10; oil temperature detection means 31 which detects a temperature OT of the lubricant; and control means 30 which dilutes the lubricant by supplying a prescribed amount of fuel to the oil pan 21 by operating the supply means 14 when a supply condition including that the temperature OT of the lubricant which is detected by the oil temperature detection means 31 is equal to or lower than a first prescribed temperature Tis established. 【課題】燃費向上と耐久信頼性とを両立することができるようにした、エンジンの潤滑油粘度調節装置を提供する。【解決手段】エンジン２０の潤滑油が貯留されるオイルパン２１と、燃料タンク１０から燃料をオイルパン２１へ供給する供給手段１４が介装された第一経路１１と、オイルパン２１内において潤滑油から揮発した燃料を燃料タンク１０へ戻す第二経路１２と、潤滑油の温度OTを検出する油温検出手段３１と、油温検出手段３１で検出された潤滑油の温度OTが第一所定温度T1以下であることを含む供給条件が成立した場合に、供給手段１４を作動させて所定量の燃料をオイルパン２１へ供給して潤滑油を希釈する制御手段３０と、を備える。【選択図】図１