Manufacturing method of sleeve

• Main Author: SHIU, JIA-LIN
• Format: Patent
• Language: Chinese; English
• Published: 16.10.2007
• Subjects: MAKING METAL CHAINS; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; PERFORMING OPERATIONS; PUNCHING METAL; TRANSPORTING

This invention relates to a manufacturing method of a sleeve used for repeatedly punching a wire material to form a hollow sleeve, the manufacturing method comprising the steps of: cutting a wire material into a blank with a certain length; preliminarily punching the blank into a pre-punched blank with a top face having the central part slightly concaved downward; deep drawing and extruding the pre-punched blank into a deep punched blank with a top face having the central part concaved deeply downward to form a deep dent and a bottom face curvedly concaved to form a curved dent, and forming a separating wall between the deep dent and the curved dent; cutting and punching out the separating wall of the deep punched blank for form a hollow sleeve. With the aforementioned deep drawing and extruding process, the shape of the separating wall can be designed to be flat upper and curved lower, capable of increasing the strength and improving the cracking problem, so as to achieve the efficacies of reducing productio