Synchronizer hub for vehicles and method for manufacturing the same

Abstract

A synchronizer hub for vehicles and a method for manufacturing the same forms an inner spline and an outer spline of a transmission synchronizer hub for vehicles by using different materials. The synchronizer hub may be manufactured by filling inner powders for forming the inner spline, molding the inner spline, filling outer powders for forming the outer spline, molding the outer spline, separating the double molded object obtained by integrally forming the inner spline and the outer spline from a mold, and performing sintering, post-processing, and high-frequency heating processes.

1 - 6 . (canceled) 
     
     
         7 . A method for manufacturing a synchronizer hub for vehicles, comprising:
 filling inner powders for forming an inner spline in a first space formed between a mold main body, a first mold positioned on an upper side, and a second mold positioned on a lower side;   press-molding the inner powders in the second mold by using a first press to form the inner spline;   moving the first mold to the lower side, and filling outer powders for forming an outer spline in a second space formed between the mold main body, the first mold, and the molded inner spline;   rotating an upper part of a press by approximately 180 degrees to change a position of the first press to a second press, and press-molding the outer powders by using the second press to integrally form the outer spline and the inner spline;   raising the first mold and the second mold to the upper side to separate a double molded object obtained by integrally forming the inner spline and the outer spline from a mold; and   performing a sintering process, a post-processing process, and a high-frequency heating process on the double molded object.   
     
     
         8 . The method for manufacturing the synchronizer hub for vehicles of  claim 7 , wherein in the step of press-molding the inner powders, the first press is applied to the inner powders at a room temperature under a pressure of 6.5 to 7.5 g/cm3. 
     
     
         9 . The method for manufacturing the synchronizer hub for vehicles of  claim 7 , wherein in the step of press-molding the outer powders, the second press is applied to the outer powders under a pressure of 6.6 to 7.6 g/cm3, which is relatively greater than a pressing pressure of the inner powders. 
     
     
         10 . The method for manufacturing the synchronizer hub for vehicles of  claim 7 , wherein the sintering process is performed in a sintering furnace at a temperature of about 1000 to 1300° C. under a gas mixture atmosphere of hydrogen and nitrogen for about 20 minutes to one hour. 
     
     
         11 . The method for manufacturing the synchronizer hub for vehicles of  claim 7 , further comprising:
 cooling the double molded object by controlling a cooling velocity to be 0.2 to 0.60 □C/sec between the sintering process and the post-processing process.   
     
     
         12 . The method for manufacturing a synchronizer hub for vehicles of  claim 7 , wherein the heating process is performed by performing a high-frequency heating process on a boss by using a cylindrical coil. 
     
     
         13 - 18 . (canceled)