Patent ID: 6678574
Filing Date: 2004-01-13
Classification: B21J,B21K,B60G,Y10T

Abstract:
A method for producing suspension parts of aluminum alloy, said method comprising a step off preparing a workpiece for roll forming having prescribed dimensions, a step of heating said workpiece, a step of subjecting said workpiece, which has been heated, to roll forming, thereby giving a preformed workpiece, a step of subjecting said preformed workpiece to pressing or forging in multiple stages, thereby giving a formed product, and a step of subjecting the formed product to trimming, wherein said trimming is carried out only after the above-mentioned pressing in multiple stages has been completed,wherein the prescribed dimensions are determined by steps of establishing an imaginary center line in the suspension part of aluminum alloy, acquiring plural orthogonal cross-sections perpendicular to the imaginary center line so as to be arranged along the imaginary center line, calculating a sectional area of the cross-sections, defining imaginary circles each having an imaginary area which is equal to the sectional area of the orthogonal cross-section plus a preliminarily established amount of flash, defining the imaginary area between said imaginary circles by interpolation, integrating said imaginary areas, thereby calculating the imaginary total volume of the suspension part of aluminum alloy, and obtaining the sectional area of the workpiece of roll forming based on the imaginary circle having the maximum area among said imaginary circles and dividing said total volume by said sectional area, thereby giving a value which is regarded as the length of the workpiece for roll forming.