Patent ID: 7124731

Claim:
An internal combustion engine comprising: an engine body in which a combustion space and a valve system housing chamber have been formed longitudinally, wherein the valve system housing chamber forms a return path for return lubrication oil; a valve system housed in said valve system housing chamber, the valve system including a valve train for opening and closing an intake valve and an exhaust valve; and a sensor for detecting an engine drive state, said sensor being connected to a side of said engine body such that an external portion of said sensor is disposed outside of said engine body and an internal portion of said sensor is in fluid communication with lubrication oil, wherein said valve system housing chamber includes a chamber wall having an oil reservoir for storing lubricating oil, and said sensor comprises an oil temperature sensor for detecting the temperature of the lubrication oil in said oil reservoir; and wherein the valve system further comprises driving force transmission members, and said oil reservoir is provided with an outflow passage for supplying the lubricating oil which overflows from said oil reservoir to said driving force transmission members.