Occupant protecting device for use in motor vehicles

• US 5,631,834 A
• Filed: 02/15/1996
• Issued: 05/20/1997
• Est. Priority Date: 05/20/1993
• Status: Expired due to Term

• Current Assignee: Kansei Company
• Original Assignee: Kansei Company
• Inventors: Saito, Yasuo, Kaneko, Kunihiro, Ohneda, Katsushi, Matsumori, Satoru, Tsurushima, Shin-ichiro, Kon, Kazuyasu
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): Walker, Tyrone V.
• Application Number:
  US08/601,873
• Time in Patent Office: 460 Days
• Field of Search: 364/424.05, 340/438, 340/436, 280/735, 280/734, 180/282, 180/274, 307/10.1
• US Class Current: 701/45
• 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 21/0133 by integrating the amplitude of the input signal
• CPC Class Codes: B60R 21/017 including arrangements for providing electric power to safety arrangements or their actuating means, e.g. to pyrotechnic fuses or electro-mechanic valves
• CPC Class Codes: B60R 21/0173 Diagnostic or recording means therefor

Abstract

An occupant protecting device for a motor vehicle, which inflates an air-bag system reliably to protect occupants in the event of a collision with high reliability. The occupant protecting device includes an acceleration sensor for sensing an acceleration signal of a vehicle in the event of collision with another vehicle or the like, a signal processor for detecting a collision waveform from an acceleration signal output from the acceleration sensor, a comparator for determining whether or not the output signal of the signal processor exceeds a preset level to produce a trigger signal when it exceeds the preset level, a latch circuit for latching the trigger signal from the comparator, and a firing circuit for operating an occupant protecting unit in response to a drive signal from the latch circuit.

Claims

1. A drive device for a vehicle occupant protecting device comprising:

an auxiliary power source which is charged by a DC power source;

an igniting device;

a switching element connected between a point connecting the DC power source with said auxiliary power source and said igniting device; and

a control circuit for judging a magnitude of a collision based on an acceleration signal supplied from an acceleration sensor to provide a trigger signal to said switching element thereby electrically connecting said auxiliary power source to said ignition device when it is judged that an accident has occurred, said control circuit detecting an output voltage of said auxiliary power source.

wherein said control circuit comprising a pulse-width varying circuit for varying a pulse width of the trigger signal in inverse proportion to the output voltage,

and wherein a predetermined energy necessary to fire said ignition device is determined by said output voltage and said pulse width, and said control circuit varies said pulse width to deliver said predetermined energy to said ignition device.

2. The drive device according to claim 1, wherein said control circuit monitors said output voltage at discrete intervals of time, and accumulates sampled values, said control signal being terminated when said accumulated sample values correspond to said predetermined energy.

3. The drive device according to claim 1, wherein said control circuit comprises an integrator for integrating said output voltage of said auxiliary power source, wherein said control signal is terminated when an output value of said integrator reaches a value corresponding to said predetermined energy.

4. The drive device according to claim 1, wherein said control circuit comprises a microcomputer for digitizing said output voltage of said auxiliary power source for a preset period of time to thereby generate digital signals which are accumulated, wherein said control signal is terminated when an accumulated value of said digital signals reaches a value corresponding to said predetermined energy.