| 摘要 |
PURPOSE:To decrease the coefficient of dynamic viscosity of lubricating oil on the inner surface of a liner part and to reduce a friction loss between a cylinder and a piston, by a method wherein, in a device provided at the outer periphery of a liner part with a water cooling chamber, the thickness of the liner part is so formed that its lower part is thicker than its upper part. CONSTITUTION:Cooling water, discharged from a cooling water 21, flows to the lower part of a cooling water jacket 51, and after it cools the outer surface of a liner part 50, the cooling water incomes to a cooling water reservoir 24 of a cylinder head 13 through a communicating port 23 formed in an upper part. Thereafter, the cooling water flows to a thermostat 27 through a piping 26 by means of a cooling water outlet pipe 25. A part thereof further flows through a radiator 28 and a piping 29, and the remaining part flows to a cooling water pump 21 through a bypass piping 31. In this consitution, the thickness of the liner part 50 formed to the interior of a crank case 11 of a point on the the liner part increases the further downward along the liner part this point is situated. This causes the width of a cooling jacket 51 of this point along its surface to decrease the further downward along its surface this point is situated, resulting in the possibility to prevent cooling of the lower part of the liner part 50 to achieve a desired purpose. |
