Abstract

The purpose of the present invention is to provide a vacuum booster device such that the length of an attachment portion on the attached member side of a tie rod bolt can be increased while limiting an increase in the size of a tie rod bolt forging device. An attachment portion (rear end portion) on the attached member side of a tie rod bolt of a vacuum booster device includes a screw lower part, an extension part, and swaging part formed in that order from an end (rear end) thereof. A screw lower diameter that is the outer diameter of the screw lower part, an extension part diameter that is the outer diameter of the extension part, and a swaging part diameter that is the outer diameter of the swaging part are set to be larger in that order.

IPC Classes  ?

• B60T 13/567 - Vacuum systems indirect, i.e. vacuum booster units characterised by constructional features of the casing or by its strengthening or mounting arrangements