METHOD FOR THE PRODUCTION OF A HIGH-PRESSURE ACCUMULATOR PIPE MADE OF STEEL FOR FUEL INJECTION SYSTEMS AND HIGH-PRESSURE ACCUMULATOR PIPE PRODUCED ACCORDING TO THIS METHOD

摘要

The invention relates to a method for the production of a high-pressure a ccumulator pipe as a composite pipe made of steel for pressures up 1800 bar and above and having high static stability and endurance strength for fuel i njection systems comprising common rail systems for internal combustion engi nes, wherein a first inner pipe part (2) is inserted into a second outer pip e part (1) with little clearance, and the inner pipe part (2) is connected t o the outer pipe part (1) in a gap-free and non-positive connection by means of mechanical forming. To achieve a high endurance strength, the mechanical forming comprises a rolling-in process, wherein the inner pipe part (2) is subjected to a ductile expansion, and the outer pipe part (1) is subjected t o an elastic expansion using an oversized rolling tool that is moved within the inner pipe part (2) and wherein a residual compressive stress adjusted t o the operating pressure is applied to the inner pipe part (2) after the for ming process via the elastic resilience of the outer pipe part. The high-pre ssure accumulator pipe produced in this manner is characterized in that the inner surface of the inner pipe part (2) has a roughness Rz with the range o f <= 1.0 µ and a roughness Ra within the range of <= 0.2 µm.