Patent ID: 6705329
Filing Date: 2004-03-16
Classification: B21C,F02M,Y10T

Abstract:
A method of manufacturing a small-diameter thick-wall high-pressure fuel injection pipe for use in an internal combustion engine consisting of the steps of performing a plurality of cycles of pipe-extending process and pipe heating process, and after performing a final of said cycles of pipe-extending process and pipe heating process, performing steps of cleaning and removing at least a first type of minute foreign particles present from outside sources and adhering to the inner circumferential surfaces of the pipe, by applying to said surfaces a first solvent for dissolving the first type of foreign particles adhered to the inner circumferential surfaces of the pipe and then cleaning and removing at least a second type of minute foreign particles present from outside sources and adhering to the inner circumferential surfaces of the pipe by applying to said surfaces at least a second solvent for dissolving the second type of foreign particles adhered to the inner circumferential surfaces of the pipe, wherein the first and second solvents are different from one another.