METHOD OF MANUFACTURING ALUMINUM DIE CAST STEERING COLUMN AND STEERING COLUMN

• Main Authors: MITSUMURA MUNETAKA, OKITA SHIGERU
• Format: Patent
• Language: English; Japanese
• Published: 04.12.2014
• Subjects: CASTING; CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES; LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS; MOTOR VEHICLES; PERFORMING OPERATIONS; POWDER METALLURGY; TRAILERS; TRANSPORTING

PROBLEM TO BE SOLVED: To provide an aluminum die cast steering column manufacturing method capable of taking out a manufacturing product in a zero extraction gradient, and a steering column for not generating an abnormal sound when sliding an inner column even in an inner diameter part formed of a core of the zero extraction gradient.SOLUTION: A solidification state of the steering column 1 in aluminum die cast time is predicted in advance, and an easily cooling part is heated or warmed by a heater 7, and in a hardly cooling part, a manufacturing product can be taken out in the zero extraction gradient by uniformizing the solidification temperature of the manufacturing product to the preset temperature by making cooling water communicating with the casting mold inside approach the manufacturing product. In the steering column of the present embodiment, the abnormal sound is not generated when sliding the inner column by setting surface roughness of the inner diameter part formed of the core of the zero extraction gradient to Ra=0.8 μm or less, desirably, Ra=0.7 μm or less. 【課題】抜き勾配ゼロで製造品を取り出すことが可能なアルミダイカスト製ステアリングコラム製造方法、及び抜き勾配ゼロの中子で形成された内径部でもインナーコラム摺動時に異音が発生しないステアリングコラムを提供する。【解決手段】予めアルミダイカスト時のステアリングコラム１の凝固状況を予測し、冷えやすい部分をヒーター７で加熱又は加温し且つ冷えにくい部分は鋳型中に通じる冷却水を製造品に接近して製造品の凝固温度を予め設定された温度に均一化することで抜き勾配ゼロで製造品を取り出すことが可能となる。また、本実施形態のステアリングコラムでは、抜き勾配ゼロの中子で形成された内径部の表面粗さをＲａ＝０．８μｍ以下、好ましくはＲａ＝０．７μｍ以下とすることにより、インナーコラムの摺動時に異音が発生しない。【選択図】図３