MOLDING METHOD OF COIL SPRING AND MOLDING DEVICE

• Main Authors: GOTOU KOUJI, OKURA SHINSUKE, YAMASHITA TAKASHI
• Format: Patent
• Language: English; Japanese
• Published: 09.04.2015
• Subjects: MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; PERFORMING OPERATIONS; PUNCHING METAL; TRANSPORTING; WORKING OR PROCESSING OF METAL WIRE

PROBLEM TO BE SOLVED: To form a pitch of an end coil part of a coil spring into a desired pitch when molding a pigtail at an end of the coil spring.SOLUTION: This manufacturing method of a coil spring comprises a first molding step of molding the coil spring into a cylindrical shape by winding a raw material of the coil spring to a first core metal, and a second molding step of additionally processing an end of the cylindrically-molded coil spring. The second molding step comprises a step of cramping a specified region at a portion other than one end of the raw material of the cylindrically-molded coil spring, a step of cramping one end of the raw material of the cylindrically-molded coil spring, and a moving step of at least moving one end of the raw material which is cramped to the cramped specified region to an axial line direction of the cylindrically-molded coil spring. 【課題】 コイルばねの端部にピッグテールを成形する際に、コイルばねの座巻部のピッチを所望のピッチに成形する。【解決手段】 このコイルばねの製造方法は、コイルばねの素線を第１の芯金に巻き付けることで円筒状に成形する第１成形工程と、円筒状に成形したコイルばねの端部を追加工する第２成形工程を備えている。第２成形工程は、円筒状に成形したコイルばねの素線の一端以外の特定部位をクランプするステップと、円筒状に成形したコイルばねの素線の一端をクランプするステップと、クランプされた特定部位に対してクランプされた素線の一端を、円筒状に成形したコイルばねの軸線方向に少なくとも移動させる移動ステップを備えている。【選択図】 図２