| 摘要 |
PURPOSE:To reduce blowby by making a plurality of shallow radial grooves in the upper face of top ring groove of piston. CONSTITUTION:A plurality of shallow radial grooves 6 are made in the upper face of top ring groove 2 of piston 1. Since gas between top ring and second ring will escape quickly through a groove 6 to the top face direction of piston 1, the inter-ring pressure will decrease quickly to move the rised top ring to the under face side of top ring groove 2. Consequently, blowby can be reduced. |
