Air bag system as a supplementary restraint system to seat belt apparatus

• US 6,198,997 B1
• Filed: 09/24/1998
• Issued: 03/06/2001
• Est. Priority Date: 09/25/1997
• Status: Expired due to Fees

• Current Assignee: Mazda Motor Corporation
• Original Assignee: Mazda Motor Corporation
• Inventors: Takagi, Takeshi, Tsukiji, Yutaka, Ishikawa, Toshihiro
• Primary Examiner(s): Louis-Jacques, Jacques H.
• Assistant Examiner(s): Broadhead, Brian J.
• Application Number:
  US09/159,593
• Time in Patent Office: 894 Days
• Field of Search: 701/45, 701/48, 280/734, 280/735, 307/10.1, 340/436, 340/438, 180/271, 180/272, 180/282
• US Class Current: 701/45
• CPC Class Codes: B60R 2021/01313 monitoring the vehicle steering system or the dynamic control system
• CPC Class Codes: B60R 2021/01322 comprising variable thresholds, e.g. depending from other collision parameters
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• CPC Class Codes: B60R 21/0154 in combination with seat heating
• CPC Class Codes: B60R 21/01546 using belt buckle sensors

Abstract

An air bag system comprises a crash detector for detecting a crash of the vehicle, an inflator for generating pressurized gas in response to a detection of a crush, and an air bag located in front of a seat for which is inflated and expanded with the pressurized gas to a predetermined inflated configuration. A control unit controls actuation of the inflator in accordance with driving conditions and whether or not the passenger is fastened by the seat belt. Threshold values are provided such that the inflator provides high and low levels of gas pressure with which the air bag is inflated and expanded.

Claims

1. An air bag system as a supplementary restraint system to a seat belt device for a vehicle in which an air bag is inflated and expanded with high or low inflation pressure according to driving conditions, said air bag system comprising:

seat belt detection means for detecting whether a seat belt is buckled up;

crash condition detection means for detecting a parameter relating to one of a crash acceleration and a crash velocity at a crash of said vehicle;

inflating means for generating high and low levels of inflation pressure with which said air bag is inflated and expanded;

angle detection means for detecting a steered angle of said vehicle; and

control means for controlling said inflating means to generate said low level of inflation pressure when said crash condition detection means detects a first threshold value of said parameter and said high level of inflation pressure when said crush condition detection means detects a second threshold value greater than said first threshold value when said belt detection means detects that said seat belt is not buckled up, and to generate said low level of inflation pressure when said crash condition detection means detects a third threshold value of said parameter and said high level of inflation pressure when said crash condition detection means detects a fourth threshold value greater than said third threshold value when said seat belt detection means detects that said seat belt is buckled up;

wherein said third threshold value and said fourth threshold value are determined so as to be greater than said first threshold value and said second threshold value, respectively, and said control means decreases said first threshold value and said third threshold value smaller as said steered angle is increase.

2. The air bag system as defined in claim 1, wherein said control means varies said first threshold value by a first decrement and third threshold value by a third decrement smaller than said first decrement for each specific point of said steered angle.

3. An airbag system as a supplementary restraint system to a seat belt device for a vehicle in which an air bag is inflated and expanded with high and low inflation pressure according to driving conditions, said air bag system comprising:

seat belt detection means for detecting whether a seat belt is buckled up;

crash condition detection means for detecting a parameter relating to one of a crash acceleration and a crash velocity at a crash of said vehicle;

inflating means for generating high and low levels of inflation pressure with which said air bag is inflated and expanded;

speed section means for detecting a vehicle speed of said vehicle; and

control means for controlling said inflating means to generate said low level of inflation pressure when said crash condition detection means detects a first threshold value of said parameter and said high level of inflation pressure when said crash condition detection means detects a second threshold value greater than said first threshold value while said seat belt detection means detects that said seat belt is not buckled up, and to generate said low level of inflation pressure when said crash condition detection means detects a third threshold value of said parameter and said high level of inflation pressure when said crash condition detection means detects a fourth threshold value greater than said third threshold value while said seat belt detection means detects that said seat belt is buckled up;

wherein said third threshold value and said fourth threshold value are determined so as to be greater than said first threshold value and said second threshold value, respectively, and control means decreases said second threshold value and said fourth threshold value as said vehicle speed is increased such that a rate of change relative to a change in said vehicle speed is greater for said second threshold value than for said fourth threshold value.

4. An air bag system as defined in claim 3, wherein said second threshold value is decreased when said vehicle speed is higher than a first specified speed, and said fourth threshold value is decreased when said vehicle speed is higher than a second specified speed which is greater than said first specified speed.

5. An air bag system as defined in claim 3, wherein said first threshold value is decreased when said vehicle speed is higher than first specified speed, and said third threshold value is decreased when said vehicle speed is higher than a second specified speed which is greater than said first specified speed.

6. An air bag system as a supplementary restraint system to a seat belt device for a vehicle in which an air bag is inflated and expanded with high and low inflation pressure according to driving conditions, said air bag system comprising:

seat belt detection means for detecting whether a seat belt is buckled up;

crash condition detection means for detecting a parameter relating to one of a crash acceleration and a crash velocity at a crash of said vehicle;

inflating means for generating high and low levels of inflation pressure with which said air bag is inflated and expanded;

speed detection means for detecting a vehicle speed of said vehicle; and

control means for controlling said inflating means to generate said low level of inflation pressure when said crash condition detection means detects a first threshold value of said parameter and said high level of inflation pressure when said crash condition detection means detects a second threshold value greater than said first threshold value while said seat belt detection means detects that said seat belt is not buckled up, and to generate said low level of inflation pressure when said crash condition detection means detects a third threshold value of said parameter and said high level of inflation pressure when said crash condition detection means detects a fourth threshold value greater than said third threshold value while said seat belt detection means detects that said seat belt is buckled up;

wherein said third threshold value and said fourth threshold value are determined so as to be greater than said first threshold value and said second threshold value, respectively, and said control means decreases said first threshold value and said third threshold value as said vehicle speed is increased such that a rate change relative to a change in said vehicle speed is greater for first threshold value than for said third threshold value.

7. An air bag system as a supplementary restraint system to a seat belt device for a vehicle in which an air bag is inflated and expanded with high and low inflation pressure according to driving conditions, said air bag system comprising:

seat belt detection means for detecting whether a seat belt is buckled up;

crash condition detection means for detecting a parameter relating to one of a crash acceleration and a crash velocity at a crash of said vehicle;

inflating means for generating high and low levels of inflation pressure with which said air bag is inflated and expanded;

speed detection means for detecting a vehicle speed of said vehicle; and

control means for controlling and inflating means to generate said low level of inflation pressure when said crash condition detection means detects a first threshold value of said parameter and said high level of inflation pressure when said crash condition detection means detects a second threshold value greater than said firs threshold value while said seat belt detection means detects that said seat belt is not buckled up, and to generate said low level of inflation pressure when said crash condition detection means detects a third threshold value of said parameter and said high level of inflation pressure when said crash condition detects a fourth threshold value greater than said third threshold value while said seat belt detection means detects that said seat belt is buckled up;

wherein said first threshold value is a lower limit of a range of said parameter in which said air bag inflated and expanded with said low level of inflation pressure has a higher impact absorbing effect on a passenger while said seat belt is not buckled up than said air bag not inflated and expanded, said second threshold value is a lower limit of a range of said parameter in which said air bag inflated and expanded with said high level of inflation pressure has a higher impact absorbing effect on a passenger when said seat belt is not buckled up than said air bag inflated and expanded with said low level of inflation pressure while said seat belt is not buckled, up, said third threshold value is a lower limit of a range of said parameter in which said air bag inflated and expanded with said low level of inflation pressure has a higher impact absorbing effect on an passenger while said seat belt is buckled up than said air bag not inflated and expanded, and said fourth threshold value is a lower limit of a range of said parameter in which said air bag inflated and expanded with said high level of inflation pressure has a higher impact absorbing effect on a passenger while said seat belt is buckled up than said air bag inflated and expanded with said low level of inflation pressure while said seat belt is buckled up; and

wherein said third threshold value and said fourth threshold value are determined so as to be greater than said first threshold value and said second threshold value, respectively, and said control means decreases said first threshold value and said second threshold value as said vehicle speed is increased such that a rate of change relative to a change in said vehicle speed is greater for said second threshold value than for said first threshold value.

8. An air bag system as a supplementary restraint system to a seat belt device for a vehicle in which an air bag is inflated and expanded with high and low inflation pressure according to driving conditions, said air bag system comprising:

seat belt detection means for detecting whether a seat belt is buckled up;

crash condition detection means for detecting a parameter relating to one of a crash acceleration and a crash velocity at a crash of said vehicle;

inflating means for generating high and low levels of inflation pressure with which said air bag is inflated and expanded;

speed detection means for detecting a vehicle speed of said vehicle; and

control means for controlling said inflating means to generate said low level of inflation pressure when said crash condition detection means detects a first threshold value of said parameter and said high level of inflation pressure when said crash condition detection means detects a second threshold value grater than said first threshold value while said seat belt detection mean detects that said seat belt is not buckled up, and to generate said low level of inflation pressure when said crash condition detection means detects a third threshold value of said parameter and said high level of inflation pressure when said crash condition detection means detects a fourth threshold value greater than said third threshold value while said seat belt detection means detects that said seat belt is buckled up;

wherein said first threshold value is a lower limit of a range of said parameter in which said air bag inflated and expanded with said low level of inflation pressure has a higher impact absorbing effect on a passenger while said seat belt is not buckled up than said air bag not inflated and expanded, said second threshold value is a lower limit of a range of said parameter in which said air bag inflated and expanded with said high level of inflation pressure has a higher impact absorbing effect on a passenger while said seat belt is not buckled up than said air bag inflated and expanded with said low level of inflation pressure while said seat belt is not buckled up, said third threshold value is a lower limit of a range of said parameter in which said air bag inflated and expanded with said low level of inflation pressure has a higher impact absorbing effect on a passenger while said seat belt is buckled up than said air bag not inflated and expanded, and said fourth threshold value is a lower limit of a range of said parameter in which said air bag inflated and expanded with said high level of inflation pressure has a higher impact absorbing effect on a passenger while said seat belt is buckled up than said air bag inflated and expanded with said low level of inflation pressure while said seat belt is buckled up; and

wherein said third threshold value and said fourth threshold are determined so as to be greater than said first threshold value and said second threshold value, respectively, and said control means decreases said third threshold value and said fourth threshold value as said vehicle speed is increased such that a rate of change relative to a change in said vehicle speed is greater for said fourth threshold value than for said third threshold value.

9. An air bag system as a supplementary restraint system to a seat belt device for a vehicle in which an air bag is inflated and expanded with high and low inflation pressure according to driving conditions, said air bag system comprising:

seat belt detection means for detecting whether a seat belt is buckled up;

crash condition detection means for detecting a parameter relating to one of a crash acceleration and a crash velocity at a crash of said vehicle;

inflating means for generating high and low levels of inflation pressure with which said air bag is inflated and expanded;

angle detection means for detecting a steered angle of said vehicle; and

control means for controlling said inflating means to generate said low level of inflation pressure when said crash condition detection means detects a first threshold value of said parameter and said high level of inflation pressure when said crash condition detection means detects a second threshold value greater than said first threshold value while said seat belt detection means detects that said seat belt is not buckled up, and to generate said low level of inflation pressure when said crash condition detection means detects a third threshold value of said parameter and said high level of inflation pressure when said crash condition detection means detects a fourth threshold value greater than said third threshold value while said seat belt detection means detects that said seat belt is buckled up;

wherein said third threshold value and said fourth threshold value are determined so as to be greater than said first threshold value and said second threshold value, respectively, and said control means decreases said first threshold value as said steered angle is increased while leaving said third threshold value unchanged.

10. An air bag system as a supplementary restraint system to a seat belt device for a vehicle in which an air bag is inflated and expanded with high and low inflation pressure according to driving conditions, said air bag system comprising:

seat belt detection means for detecting whether a seat belt is buckled up;

crash condition detection means for detecting a parameter relating to one of a crash acceleration and a crash velocity at a crash of said vehicle;

inflating means for generating high and low levels of inflation pressure with which said air bag is inflated and expanded;

angle detection means for detecting a steered angle of said vehicle; and

control means for controlling said inflating means to generate said low level of inflation pressure when said crash condition detection means detects a first threshold value of said parameter and said high level of inflation pressure when said crash condition detection means detects a second threshold value greater than said first threshold value while said seat belt detection means detects that said seat belt is not buckled up, and to generate said low level of inflation pressure when said crash condition detection means detects a third threshold value of said parameter and said high level of inflation pressure when said crash condition detection means detects a fourth threshold value greater than said third threshold value while said seat belt detection means detects that said seat belt is buckled up;

wherein said third threshold value and said fourth threshold value are determined so as to be greater than said first threshold value and said second threshold value, respectively, and said control means decreases said second threshold value and said fourth threshold value as said steered angle is increased.