On an end portion (20a) of a hollow rod (20), which is a material of a hollow coil spring (10), a terminal sealed portion (30) is formed. The terminal sealed portion (30) has a rotationally symmetric shape in which an axis (X1) passing through the center of the rod (20) is a symmetric axis. The terminal sealed portion (30) includes an end wall portion (41), and a distal-end-center closure portion (43) formed on the axis (X1). In the distal-end-center closure portion (43), a distal end opening portion of the spin-formed rod (20) is joined together and formed as an integral part. On the axis (X1) at the inner surface of the end wall portion (41), a recess (45) having a rotationally symmetric shape in which the axis (X1) is the symmetric axis is formed. A thickness (t) of the recess (45) of the end wall portion (41) is reduced toward the axis (X1) .
HOLLOW SPRING MEMBER
HOHLES FEDERELEMENT
ÉLÉMENT DE RESSORT CREUX
2022-01-12
Patent
Electronic Resource
English
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