| 摘要 |
The invention relates to a belt tensioner (1) for a safety belt, comprising a belt retractor (2) which has a frame (3), a tensioner drive wheel (5) which is connected to or can be connected to a belt shaft (9) of the belt retractor (2) in a rotationally fixed manner and which is arranged between the frame (3) and the housing (4), and a tube (6) which is fixed to the frame (3) by the housing (4) and a first portion (7) of which is guided past the tensioner drive wheel (5) and a second portion (8) of which, said second portion lying opposite the first portion (7), is directed tangentially onto the tensioner drive wheel (5). The belt tensioner further comprises a pyrotechnic gas generator (10) arranged in the tube (6) and multiple mass bodies (11) which are arranged in the tube (6), are driven by pressure that can be generated by the gas generator (10), and can be brought into engagement with dome-shaped recesses (12) of the tensioner drive wheel (5) so as to transmit forces upon exiting the second portion (8) of the tube (6) and thus drive the belt shaft (9) of the belt retractor (2) in a rotational direction which retracts the safety belt. An enlarged retaining region (13) for fixing the tube (6) to the housing (4) in a formfitting manner is formed on an end of the second portion (8) of the tube (6). The invention is characterized in that a guide portion (15) with a bead (16), which protrudes on the inner face, is molded out of the tube wall, and deflects the movement path of the mass bodies (11) entering the guide portion (15) tangentially to the tensioner drive wheel (5) in the rotational direction, is formed between a tubular outlet (14) of the second portion (8) of the tube (6) and the retaining region (13) of the tube. |
