System and method for controlling an inflatable cushion

• US 6,918,611 B1
• Filed: 08/20/2002
• Issued: 07/19/2005
• Est. Priority Date: 09/28/2000
• Status: Expired due to Fees

• Current Assignee: Autoliv Development AB (Autoliv Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Pinsenschaum, Ryan T., Winters, Mark T., Schatz, Patrick, Hawthorn, Laura A., Kneisly, Ann L., Dunkle, Stephanie
• Primary Examiner(s): CULBRETH, ERIC D
• Application Number:
  US10/223,886
• Time in Patent Office: 1,064 Days
• Field of Search: 280/739, 280/735, 280/741, 280/742, 280/736, 280/743.2
• US Class Current: 280/735
• CPC Class Codes: B60R 2021/01225 control of expansion volume
• CPC Class Codes: B60R 2021/161 characterised by additional means for controlling deployment trajectory
• CPC Class Codes: B60R 2021/23382 Internal tether means
• CPC Class Codes: B60R 2021/23386 External tether means
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 2021/2765 comprising means to control the venting
• CPC Class Codes: B60R 21/01512 Passenger detection systems
• CPC Class Codes: B60R 21/01544 detecting seat belt parameters, e.g. length, tension or height-adjustment
• CPC Class Codes: B60R 21/01554 Seat position sensors
• CPC Class Codes: B60R 21/205 in dashboards
• CPC Class Codes: B60R 21/2171 specially adapted for elongated cylindrical or bottle-like inflators with a symmetry axis perpendicular to the main direction of bag deployment, e.g. extruded reaction canisters B60R21/2176 takes precedence
• CPC Class Codes: B60R 21/233 comprising a plurality of individual compartments; comprising two or more bag-like members, one within the other B60R21/232 takes precedence
• CPC Class Codes: B60R 21/2338 Tethers
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: B60R 21/276 with means to vent the inflation fluid source, e.g. in case of overpressure B60R21/30 takes precedence; venting means on inflatable member walls B60R21/239

Abstract

An air bag pressure control system for use in a vehicle is provided. The system comprises a housing, an inflatable cushion, and a dual stage inflator. The inflator generates a quantity of inflation gas to deploy the inflatable cushion from the housing. A vent opening is formed in the housing to selectively direct a portion of the inflation gas towards or away from the inflatable cushion. A sensing and diagnostic module detects an activation event level. A control algorithm tailors an inflation level of the inflatable cushion during deployment according to the activation event level.

Claims

1. An air bag pressure control system for use in a vehicle having a seating structure, comprising:

a housing being configured for installment in the vehicle;

an inflatable cushion stored in an un-deployed position in said housing, said inflatable cushion being configured for deployment towards the seating structure;

a dual stage inflator in fluid communication with said inflatable cushion, said dual stage inflator being configured to generate a quantity of inflation gas being in a range defined by a first quantity of inflation gas and a second quantity of inflation gas to deploy said inflatable cushion from said housing towards the seating structure;

a vent opening formed in said housing, said vent opening being configured to allow a portion of said first quantity of inflation gas or a portion of said second quantity of inflation gas to vent away from said inflatable cushion;

a sensing and diagnostic module for detecting an activation event level;

a control algorithm adapted to tailor an inflation level of said inflatable cushion during deployment by controlling said dual stage inflator to generate either said first quantity of inflation gas or said second quantity of inflation gas, and by controlling a tether element releasably secured to an activation mechanism to selectively retain said inflatable cushion in a profile being in a range defined by a first expanded profile and a second expanded profile, by manipulating said activation mechanism between a first position and a second position, said activation mechanism being configured to allow said portion to vent away from said inflatable cushion through said vent opening and to retain said inflatable cushion in said first expanded profile at said first position and said activation mechanism being configured to direct said portion towards said inflatable cushion and to release said inflatable cushion to said second expanded profile by releasing said tether element as said activation mechanism moves towards said second position; and

wherein said control algorithm is configured to select said inflation level from at least five discrete inflation levels.

2. The air bag pressure control system as in claim 1, wherein said actuation mechanism is moved from said first position to said second position by an initiating device.

3. The air bag pressure control system as in claim 2, wherein said initiating device is a pyrotechnic squib or a pneumatic actuator.

4. The air bag pressure control system as in claim 1, wherein said control algorithm tailors said inflation level of said inflatable cushion during deployment according to said activation event level, a seat position, and usage of a seat belt.

5. An air bag pressure control system for use in a vehicle having a seating structure with a seat belt, comprising:

a housing being configured for installment in the vehicle;

an inflatable cushion stored in an un-deployed position in said housing, said inflatable cushion being configured for deployment towards the seating structure;

a dual stage inflator stored in fluid communication with said inflatable cushion, said dual stage inflator being configured to generate a quantity of inflation gas being in a range defined by a first quantity of inflation gas and a second quantity of inflation gas to deploy said inflatable cushion from said housing towards the seating structure;

a vent opening being formed in said housing, said vent opening being configured to allow a portion of said first quantity of inflation gas or a portion of said second quantity of inflation gas to vent away from said inflatable cushion;

a sensing and diagnostic module for detecting an activation event level;

a control algorithm adapted to tailor an inflation level of said inflatable cushion during deployment by controlling said dual stage inflator to generate either said first quantity of inflation gas or said second quantity of inflation gas and by controlling a tether element releasebly secured to an activation mechanism to selectively retain said inflatable cushion in a profile being in a range defined by a first expanded profile and a second expanded profile, by manipulating said activation mechanism between a first actuation position and a second actuation position, said activation mechanism being configured to allow said portion to vent away from said inflatable cushion through said vent opening and to retain said inflatable cushion in said first expanded profile at said first actuation position and said activation mechanism being configured to direct said portion towards said inflatable cushion and to release said inflatable cushion to said second expanded profile by releasing said tether element as said activation mechanism moves towards said second actuation position;

wherein said sensing and diagnostic module detects a seat position of the seating structure with respect to said housing and whether the seat belt is in a belted state or an un-belted state;

wherein said activation event level being in a range defined by a high level and a low level, said seat position being in a range defined by a first position and a second position with respect to said housing; and

wherein said control algorithm provides;

a first discrete inflation level if said event level is said low level, said seat position is said first position, and said seat belt is in said belted state;

a second discrete inflation level if said event level is said high level, said seat position is said first position, and said seat belt is in either said belted state or said un-belted state;

a third discrete inflation level if said event level is said low level, said seat position is said first position, and said seat belt usage is said un-belted state;

a fourth discrete inflation level if said event level is said low level, said seat position is said second position, and said seat belt usage is either said belted state or said un-belted state; and

a fifth discrete inflation level if said event level is said high level, said seat position is said second position, and said seat belt usage is either said belted state or said un-belted state.

6. The air bag pressure control system as in claim 5, wherein said first discrete inflation level is zero.

7. The air bag pressure control system as in claim 5, wherein said second discrete inflation level is provided by said dual stage inflator generating said second quantity of inflation gas, said vent opening diffusing said portion away from said inflatable cushion, and said tether element retaining said inflatable cushion in said first expanded profile.

8. The air bag pressure control system as in claim 5, wherein said third discrete inflation level is provided by said dual stage inflator generating said first quantity of inflation gas, said vent opening diffusing said portion away from said inflatable cushion, and said tether element retaining said inflatable cushion in said first expanded profile.

9. The air bag pressure control system as in claim 5, wherein said fourth discrete inflation level is provided by said dual stage inflator generating said first quantity of inflation gas, said activation mechanism diffusing said portion towards said inflatable cushion, and said tether element releasing said inflatable cushion to said second expanded profile.

10. The air bag pressure control system as in claim 5, wherein said fifth discrete inflation level is provided by said dual stage inflator generating said second quantity of inflation gas, said activation mechanisms diffusing said portion towards said inflatable cushion, and said tether element releasing said inflatable cushion to said second expanded profile.

11. The air bag pressure control system as in claim 5, wherein said second position of said seat is further away from said housing than said first position of said seat.

12. A method for varying the inflation input of an inflatable cushion of an airbag module comprising:

a housing;

an inflatable cushion;

a dual stage inflator in fluid communication with the inflatable cushion, the dual stage inflator being configured to generate a quantity of inflation gas being in a range defined by a first quantity of inflation gas and a second quantity of inflation gas in order to deploy the inflatable cushion from the housing during an activation event, the second quantity being greater than the first quantity;

a vent opening in the housing, the vent opening being positioned to allow a portion of either the first quantity of inflation gas or the second quantity of inflation gas to vent away from the inflatable cushion; and

a variable tether system being configured to either restrain the expansion of the inflatable cushion or allow unrestrained expansion of the inflatable cushion, wherein actuation of the variable tether system to allow unrestrained expansion of the inflatable cushion causes a vent blocking device to block the vent opening in the housing, the method comprising;

determining if a seat is in either a first position or a second position, said first position being closer to the airbag module;

determining if a seat belt of said seat is buckled;

determining if the inflator is to be activated in accordance with an activation event to generate either the first quantity of inflation gas or the second quantity of inflation gas; and

selecting from one of at least five inflation profiles, wherein each of said inflation profiles is defined by a combination of;

the quantity of inflation gas generated;

restraint of the expansion of the inflatable cushion by the variable tether system or unrestrained expansion of the inflatable cushion by the variable tether system; and

blocking of the vent opening or unblocking of the vent opening.

13. The method as in claim 12, wherein blocking of the vent opening is achieved by manipulating a vent blocking device into a vent blocking position by activating a pyrotechnic squib.

14. An inflatable restraint system for a vehicle having a seat with a seat belt, comprising:

an airbag module comprising;

a housing;

an inflatable cushion, said inflatable cushion being configured for deployment out of said housing;

a dual stage inflator in fluid communication with said inflatable cushion, said dual stage inflator being configured to generate a first inflation output and a second inflation output for deploying said inflatable cushion, said first inflation output being less than said second inflation output;

a vent opening disposed in said housing, said vent opening being positioned to allow a portion of either said first inflation output or said second inflation output to vent away from said inflatable cushion; and

a variable tether system being configured to either restrain the expansion of the inflatable cushion in at least one direction or to allow unrestrained expansion of the inflatable cushion, wherein actuation of the variable tether system to allow unrestrained expansion of the inflatable cushion causes a vent blocking device to block the vent opening in the housing;

a control algorithm for determining how to tailor the deployment of said inflatable cushion during an activation event, wherein said control algorithm tailors the deployment of said inflatable cushion by providing one of at least five inflation outputs to said inflatable cushion by;

determining if the seat is in either a first position or a second position, said first position being closer to the airbag module;

determining if the seat belt of the seat is buckled;

determining if said dual stage inflator is to be activated and whether to activate said dual stage inflator at either said first inflation output or said second inflation output and determining if said variable tether system is to restrain the expansion of said inflatable cushion; and

wherein activation of said dual stage inflator to generate either said first inflation output or said second inflation output and restraint of the expansion of said inflatable cushion is determined by the severity of the activation event, the position of the seat and whether the seat belt is buckled.

15. The inflatable restraint system as in claim 14, wherein said variable tether system comprises a tether having a first end and a second end, said first end being secured to an inner surface of the inflatable cushion and the second end being secured to an actuatable member having said vent blocking device secured thereto, said actuatable member being configured for movement between a first position and a second position, wherein a length of said tether limits the deployment of said inflatable cushion in at least one direction when said second end is retained by said actuatable member and actuation of said actuatable member from said first position to said second position releases said second end and said vent blocking device is positioned to block said vent opening when said actuatable member moves from said first position to said second position.

16. A method for providing one of at least five inflation outputs to an inflatable cushion of an airbag module disposed proximate to a seat of a vehicle, the seat having a seat belt and the airbag module having an inflator for inflating the inflatable cushion, the method comprising:

determining the position of the seat relative to the airbag module;

determining if the seat belt of said seat is buckled;

determining the severity of an inflator activation event;

determining if the inflator is to be activated in accordance with the activation event and whether to generate either a first quantity of inflation gas or a second quantity of inflation gas, the second quantity of inflation gas being greater than the first quantity of inflator gas;

determining whether to release a restraining tether secured to a portion of the inflatable cushion, wherein release of the restraining tether causes a vent opening of the airbag module to be blocked; and

providing one of the at least five inflation outputs, wherein the provided inflation output is defined by a combination of;

the quantity of inflation gas generated;

release of the restraining tether; and

blocking of the vent opening.