| 摘要 |
<p>It is aimed to provide a seatbelt retractor whose manufacturing cost is reduced. A retractor includes a windup drum that winds webbing and a pretensioner unit that causes the windup drum to rotate in a windup direction of the webbing. The pretensioner unit includes a pinion gear configured to rotate in association with the windup drum, a piston that includes a rack for meshing with the pinion gear (165) and causes the windup drum to rotate in the windup direction through the pinion gear, a tubular cylinder that has a circular cross-section and movably holds the piston, and a drive mechanism that drives the piston. The piston further includes, on a rear surface side of the rack, a contact surface configured to come into contact with an inner wall of the cylinder, and the cylinder has such a tube length as not to expose the contact portion in a movable range of the piston.</p> |
