Internal combustion engine piston oil ring groove structure and mounting using method thereof

The invention discloses an internal combustion engine piston oil ring groove structure and a mounting using method thereof. The internal combustion engine piston oil ring groove structure is characterized in that the internal combustion engine piston oil ring groove structure is distributed at a third ring groove in the head of a piston and comprises a rectangular groove and an oil returning hole, the oil returning hole penetrates to a piston inner cavity from the bottom of a third rectangular groove, the section of the oil returning hole is in a circular shape, the oil returning hole is formed by mechanical hole drilling machining, the oil returning hole leads to the piston inner cavity from the bottom of the third rectangular groove obliquely downwards, and the included angle between the center line of the oil returning hole and the horizontal direction is 5-75 degrees. The structure is simple, designing is reasonable, the manufacturing technology is good, the phenomenon that engine oil does not flow in the oil ring groove for a long time, so that engine oil is too hot and goes bad is avoided, the problem that too much engine oil is accumulated in the oil ring groove and enters a burning chamber is avoided, engine oil loss of an internal combustion engine can be well lowered, the using economy of the internal combustion engine is improved, and great promotion and application value is achieved.