On an end portion of a hollow rod, which is a material of a hollow coil spring, a terminal sealed portion is formed. The terminal sealed portion has a rotationally symmetric shape in which an axis passing through the center of the rod is a symmetric axis. The terminal sealed portion includes an end wall portion, and a distal-end-center closure portion formed on the axis. In the distal-end-center closure portion, a distal end opening portion of the spin-formed rod is joined together and formed as an integral part. On the axis at the inner surface of the end wall portion, a recess having a rotationally symmetric shape in which the axis is the symmetric axis is formed. A thickness of the recess of the end wall portion is reduced toward the axis.
HOLLOW SPRING MEMBER
2019-01-31
Patent
Electronic Resource
English
Hollow spring member and hollow spring member production method
European Patent Office | 2021
|HOLLOW SPRING MEMBER AND HOLLOW SPRING MEMBER PRODUCTION METHOD
European Patent Office | 2019
|HOLLOW SPRING MEMBER AND HOLLOW SPRING MEMBER PRODUCTION METHOD
European Patent Office | 2019
|