| 摘要 |
PURPOSE:To increase the intake-gas charging efficiency and improve the combustion efficiency by forming the unevenness of the areas which are fitted to each other, on an upper surface of a piston and a lower surface of a cylinder- head, thus permitting a swirl to be formed in a cavity by the squish flow caused by the fitting of the uneven areas when the piston rises. CONSTITUTION:Uneven areas which are fitted to each other and cause a swirl in a cavity 14 are formed on the upper surface 5a of a piston 5 and the lower surface 3a of a cylinder-head. Namely, a plurality of swirl projections 15 are fixed by means of screw bolts 16 on the upper surface 5a on the peripheral wall 14a of a cavity 14 which is formed by indenting a piston head 5b, and swirl projections 15 and swirl grooves 17 are arranged alternately, while a plurality of fitting projection 19 having an insertion groove 19 into which the swirl projection 15 is inserted are fixed on the lower surface 3a of the cylinder-head by means of screw bolts 21. Thus, a swirl is formed in the cavity 14 by the squish flow through the fitting of the uneven areas described above, in the compression cycle in which the piston 5 rises. Therefore, the intake charging efficiency can be increased, and the combustion performance is improved. |
