Seatbelt control device

A vehicle seatbelt control device comprising:

• a pretensioner mechanism that heightens tension of a seatbelt by winding the seatbelt upon a collision of a vehicle;
• a force limiter mechanism capable of changing magnitude of a load at which to start lessening the tension of the seatbelt wound by the pretensioner mechanism;
• a detection portion that detects a physical quantity related to magnitude of a collision;
• and
• a control portion that activates the pretensioner mechanism if the physical quantity detected by the detection portion has exceeded a first threshold value, and that discerns whether or not the physical quantity is likely to exceed a second threshold value that is larger than the first threshold value within a predetermined time range following activation of the pretensioner mechanism, and sets the load in a case where the physical quantity is likely to exceed the second threshold value at a load that is larger than the load in a case where the physical quantity is not likely to exceed the second threshold value within the predetermined time range.

A method of controlling the tension of a vehicle seatbelt comprising the following steps:

• detecting a physical quantity related to magnitude of a collision of a vehicle;
• activating a pretensioner mechanism if the detected physical quantity has exceeded a first threshold value;
• heightening a tension of the seatbelt by the pretensioner mechanism upon the collision;
• and
• starting lessening the tension of the seatbelt by a force limiter mechanism capable of changing magnitude of a load, wherein
• it is performed such a control that the load in a case where the physical quantity has exceeded a second threshold value that is larger than the first threshold value within a predetermined time range following activation of the pretensioner mechanism is set larger than the load in a case where the physical quantity does not exceed the second threshold value within the predetermined time range.

A method of controlling the tension of a vehicle seatbelt comprising the following steps:

• detecting a physical quantity related to magnitude of a collision of a vehicle;
• activating a pretensioner mechanism if the detected physical quantity has exceeded a first threshold value;
• heightening the tension of the seatbelt by the pretensioner mechanism upon the collision;
• and
• starting lessening the tension of the seatbelt by a force limiter mechanism capable of changing magnitude of a load, wherein
• it is discerned whether or not the physical quantity is likely to exceed a second threshold value that is larger than the first threshold value within a predetermined time range following activation of the pretensioner mechanism, and
• the load in a case where the physical quantity is likely to exceed the second threshold value is set to be larger than the load in a case where the physical quantity is not likely to exceed the second threshold value within the predetermined time range.