Device for controlling expansion of an air bag apparatus

• US 6,428,040 B2
• Filed: 12/19/2000
• Issued: 08/06/2002
• Est. Priority Date: 12/28/1999
• Status: Active Grant

• Current Assignee: Mazda Motor Corporation
• Original Assignee: Mazda Motor Corporation
• Inventors: Sakakida, Masafumi
• Primary Examiner(s): Johnson, Brian L.
• Assistant Examiner(s): WINNER, TONY H
• Application Number:
  US09/739,220
• Publication Number:
  US 20010006288A1
• Time in Patent Office: 595 Days
• Field of Search: 280/735, 701/45, 180/271, 180/282
• US Class Current: 280/735
• CPC Class Codes: B60R 2021/01006 Mounting of electrical components in vehicles
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: B60R 21/0133 by integrating the amplitude of the input signal

Abstract

A device for controlling an air bag apparatus includes a first acceleration sensor mounted in a passenger compartment for detecting an acceleration thereof and a second acceleration sensor mounted in a front portion of a vehicle body. A control unit electrically connected to the first and second acceleration sensors does not output an operation signal to a trigger circuit for inflaters until a first value derived from a signal detected by the first acceleration sensor has exceeded a first criterion and when a second value derived from a signal detected by the second acceleration sensor has exceeded a predetermined acceleration greater than an acceleration corresponding to the first criterion. In the event of a collision, because a very large impact force is applied to the front portion of the vehicle body, the control unit actuates the air bag apparatus appropriately based on the signals detected by both the first and second acceleration sensors. If a shock is applied to the vehicle body due to the run-up of a wheel onto a curb or the like, and even if the first acceleration sensor outputs a signal that allows actuation of the air bag apparatus, the second acceleration sensor does not output the operation signal, because it is not outputted until a further greater shock is applied to the vehicle body, thus preventing erroneous operation of the air bag apparatus.

Claims

1. A device for controlling an air bag apparatus including an inflatable air bag and mounted in an automotive vehicle having a passenger compartment defined therein, said device comprising:

a first acceleration sensor mounted in the passenger compartment for detecting an acceleration thereof;

a second acceleration sensor mounted in a front portion of the vehicle body; and

a control unit electrically connected to said first and second acceleration sensors so that signals from said first and second acceleration sensors are inputted to said control unit;

wherein when a first value derived from a signal detected by said first acceleration sensor has exceeded a first criterion and when a second value derived from a signal detected by said second acceleration sensor has exceeded a predetermined value greater than the first criterion, said control unit outputs an expansion signal for causing the air bag apparatus to inflate the air bag.

2. The device according to claim 1, wherein said control unit outputs the expansion signal regardless of presence or absence of the signal detected by said second acceleration sensor, when the first value has exceeded a second criterion greater than the first criterion.

3. The device according to claim 2, wherein the second criterion is greater than the predetermined value.

4. A device for controlling an air bag apparatus including an inflatable air bag and mounted in an automotive vehicle having a passenger compartment defined therein, said device comprising:

a first acceleration detector for always detecting an acceleration of the passenger compartment;

a control unit for determining necessity of operating the air bag apparatus by comparing a first value derived from a signal detected by said first acceleration detector with a first criterion; and

a second acceleration detector mounted in a front portion of the vehicle body for outputting an operation signal when a second value derived from a signal detected by said second acceleration detector has exceeded a predetermined value greater than the first criterion;

wherein when the first value has exceeded the first criterion and when said second acceleration detector has outputted the operation signal, said control unit outputs an expansion signal for causing the air bag apparatus to inflate the air bag.

5. The device according to claim 4, wherein said control unit outputs the expansion signal regardless of presence or absence of the operation signal from said second acceleration detector, when the first value has exceeded a second criterion greater than the first criterion.

6. The device according to claim 5, wherein the second criterion is greater than the predetermined value.