Assembled piston of diesel-oil engine for automobile

The utility model relates to a composite type piston, in particular to a composite type piston for on-board diesel engine, which is composed of a steel piston head and an aluminum piston skirt and is characterized in that: the threaded hole is grooved on the pin boss of the steel piston head and the steel piston head and the aluminum piston skirt are connected with bolts. During the operation of the utility model, the maximum combustion pressure of the engine is totally borne by the steel piston head, while the aluminum piston skirt receives the side thrust and partial reciprocating inertia force. Moreover, the steel piston head and the aluminum piston skirt are connected with bolts, the law of motion is identical with the integral piston and the piston head does not substantially contact the cylinder sleeve, so that the utility model is provided with such advantages as high mechanical strength and uneasy wearing, and the operating reliability and stability of the piston is improved.