Webbing take-up device

Abstract

A webbing take-up device reduced in cost by a reduction in size of a pre- tensioner and a lock device and a reduction in number of parts, wherein a plurality of projected parts (126) are formed on the inner peripheral part o f a bearing main body (124) pivotally supporting a clutch part (106) and are in linear contact with the outer peripheral part of the clutch part (106) so th at the bearing main body (124) pivotally supports the clutch part (106) indirectly through the projected parts (126), whereby, because the projected parts (126) are in linear contact with the clutch part (106), a contact area becomes extremely small and the projected parts (126) are easily deformed plastically by a frictional resistance between the projected parts (126) and the clutch part (106), and thus a resistance to prevent the clutch part (106) from rotating is reduced enough to supply a gas pressure efficiently for the rotation of a take-up shaft (20) and, as a result, those members which form the pre-tensioner (14) such as a gas generator (158) can be reduced in size and cost.

Description

technical field [0001] The invention relates to a seat belt take-up device of a seat belt device for constraining vehicle occupants by the seat belt. Background technique [0002] The seat belt take-up device, which constitutes the main part of the so-called seat belt device constrained by a long belt-shaped seat belt, is basically composed of a take-up shaft joined to one end of the seat belt, a bracket supporting the take-up shaft, and a winding shaft toward the winding shaft. The direction of taking the safety belt is composed of elastic force applying devices such as coil springs that apply elastic force to the take-up shaft. This structure is disclosed in Japanese Patents JP 10-119719 and JP 11-59330, for example. [0003] In addition, on the basis of the above structure, for example, the common safety belt take-up device disclosed in Japanese Patent JP 5-246303 and U.S. Patent US 5,794,877 is also provided with a locking device and a pretensioning device. In the case ...

AI Technical Summary

Problems solved by technology

In particular, when a synthetic resin material lower in rigidity than the metal constituting the winding shaft is used for the bearing part in order to achieve weight reduction, the above-mentioned frictional resistance causes plastic deformation of the inner peripheral part of the bearing part, and the inner peripheral surface of the bearing part Thickening, further increasing frictional resistance

[0009] Thus, in prior art seat belt reels with pretensioners, the reduction in the force required to rotate the reel shaft of the pretensioner due to frictional resistance must be considered in advance, and the gas pressure must be increased accordingly. Occurrence

Therefore, the size of the pretensioner and the size of the seat belt take-up device are increased.

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