Method for producing a unit consisting of eccentric rod and piston of a connecting rod of an internal combustion engine

A method for producing an assembly that includes an eccentric rod and a piston of a connecting rod of an internal combustion engine that has an adjustable compression ratio, the method comprising:

• providing the eccentric rod having a first end for attachment to an eccentric lever of an eccentric adjusting device of the connecting rod and a second end in the form of a ball head for attachment to a piston having a ball shell segment, the piston configured to be guided in a hydraulic chamber of the connecting rod;
• providing the piston which, in the mounted state of the connecting rod, is guided in the hydraulic chamber of the connecting rod;
• arranging the ball head of the eccentric rod partially into the ball shell segment of the piston;
• introducing an injection-molding tool into the piston by placing the injection-molding tool on a portion of the ball head of the eccentric rod that projects out of the ball shell segment so that the ball head is pressed against the ball shell segment;
• displacing at least one of the ball head and the injection molding tool in a defined manner relative to the piston to set a defined gap between the ball head and the ball shell segment;
• injection-molding a circumferentially closed retaining ring between the piston, the portion of the ball head of the eccentric rod projecting out of the piston and the injection-molding tool;
• and
• removing the injection-molding tool.