Patent ID: 8156781
Filing Date: 2012-04-17
Classification: B21D,B21K,B62D,Y10T

Abstract:
1. A method of manufacturing a steering rack, the method comprising: providing a first rack blank in a form of a pipe having a bore hole, and a second rack blank or a mandrel having such a cross-sectional shape that a gap is provided between the second rack blank or the mandrel and an inner circumferential surface of the first rack blank; inserting the second rack blank or the mandrel into the bore hole of the first rack blank; restraining an outer circumferential surface of the first rack blank at a location other than a rack teeth forming portion of the first rack blank by a first die; forming rack teeth on the first rack blank by pressing a punch having a rack teeth shaped portion onto the rack teeth forming portion of the first rack blank, and causing the first rack blank to contact an outer circumferential surface of the second rack blank or the mandrel facing the rack teeth forming portion of the first rack blank; and allowing a blank material, which has been excluded in the forming the rack teeth, to flow into the gap between the inner circumferential surface of the first rack blank and the second rack blank or the mandrel such that the blank material is accommodated in the gap and such that, after the forming of the rack teeth, a portion of the gap remains between the inner circumferential surface of the first rack blank and each side of the second rack blank or the mandrel.