Automotive passenger restraint and protection apparatus

• US 6,561,299 B2
• Filed: 05/21/2001
• Issued: 05/13/2003
• Est. Priority Date: 12/16/1997
• Status: Expired due to Term

• Current Assignee: NSK Autoliv Co., Ltd. (Autoliv Incorporated)
• Original Assignee: NSK Autoliv Co., Ltd. (Autoliv Incorporated)
• Inventors: Midorikawa, Yukinori, Kawai, Osamu
• Primary Examiner(s): Johnson, Brian L.
• Assistant Examiner(s): Bottorff, Christopher
• Application Number:
  US09/862,052
• Publication Number:
  US 20010025735A1
• Time in Patent Office: 722 Days
• Field of Search: 180/268, 180/269, 180/270, 280/802, 280/807, 280/801.1, 701/45
• US Class Current: 180/268
• CPC Class Codes: B60R 2022/4473 using an electric retraction device
• CPC Class Codes: B60R 2022/4666 characterised by electric actuators
• CPC Class Codes: B60R 21/01546 using belt buckle sensors
• CPC Class Codes: B60R 21/01548 sensing the amount of belt winded on retractor
• CPC Class Codes: B60R 22/44 with means for reducing belt tension during use under normal conditions not included in the retractor B60R22/19; B60R22/3405 takes precedence
• CPC Class Codes: B60R 22/46 Reels with means to tension the belt in an emergency by forced winding upelectrical circuits for triggering safety arrangements B60R21/01 ; tensioners using reels only guiding the belt during normal use, e.g. splitted reels B60R22/195
• CPC Class Codes: G01R 31/006 on road vehicles, e.g. automobiles or trucks testing of ignition installations peculiar to internal combustion engines F02P17/00
• CPC Class Codes: G01R 31/343 in operation

Abstract

An automotive passenger restraint and protection apparatus for an automotive vehicle has a seatbelt and operates to restrain an occupant of the automotive vehicle by the seatbelt to protect the occupant. An electric retractor has a DC motor for retracting and protracting the seatbelt. An MPU applies voltage having a predetermined waveform to the DC motor, and then detects a waveform of current flowing to the DC motor. The MPU carries out fault diagnosis of the DC motor, based upon the detected waveform of current when the voltage having the predetermined waveform is applied to the DC motor. Thus, accurate fault diagnosis of the apparatus can be achieved.

Claims

1. An automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising:

an electric retractor having a reel shaft for winding the seatbelt, and driving means comprising a DC motor for directly rotating said reel shaft in connection with rotation thereof, and said driving means retracting and protracting the seatbelt by rotating said DC motor in a forward or reverse direction respectively;

voltage waveform applying means for applying a voltage having a single waveform or continuous waveforms for a predetermined period to said driving means;

current waveform detecting means for detecting a waveform of current flowing to said driving means; and

fault diagnosis means for carrying out fault diagnosis of said driving means, based upon whether the waveform of the current detected by said current waveform detecting means exceeds a predetermined current value when said voltage waveform applying means applies the voltage having a single waveform or continuous waveforms for a predetermined period to said driving means.

2. An automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising:

an electric retractor having driving means comprising a DC motor for retracting and protracting the seatbelt by rotating said DC motor in a forward or reverse direction respectively;

a load having load characteristics equivalent to electrical characteristics of said driving means;

voltage waveform applying means for selectively applying voltage having a predetermined waveform to said driving means and said load;

current waveform detecting means for detecting a waveform of current flowing to said driving means or to said load; and

fault diagnosis means for carrying out fault diagnosis of said driving means, based on the waveform of current detected by said current waveform detecting means when said voltage waveform applying means applies the voltage having the predetermined waveform to said driving means and the waveform of current detected by said current waveform detecting means when said voltage waveform applying means applies the voltage having the predetermined waveform to said load.

3. An automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising:

an electric retractor having a reel shaft for winding the seatbelt, and driving means comprising a DC motor for directly rotating said reel shaft in connection with rotation thereof, and said driving means retracting and protracting the seatbelt by rotating said DC motor in a forward or reverse direction respectively;

warning means for giving warning upon occurrent of a fault of said driving means;

control means for controlling said driving means and said warning means; and

terminal voltage measuring means for measuring terminal voltage across said driving means when the rotation of said DC motor is driven, and when said DC motor is in an inoperative state before said DC motor begins to rotate;

wherein said control means stops operation of said driving means and causes said warning means to give warning when said driving means has continued to operate over a predetermined time period while the terminal voltage measured by said terminal voltage measuring means falls within a range between a first predetermined value and a second predetermined value.

4. An automotive passenger restraint and protection apparatus as claimed in claim 3, wherein said range between said first predetermined value and said second predetermined is a range that can be assumed when said driving means runs idle while it is functioning normally.

5. An automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising:

an electric retractor having a reel shaft for winding the seatbelt, and driving means comprising a DC motor for directly rotating said reel shaft in connection with rotation thereof, and said driving means retracting and protracting the seatbelt by rotating said DC motor in a forward or reverse direction respectively;

warning means for giving warning upon occurrent of a fault of said driving means;

control means for controlling said driving means, and said warning means; and

current detecting means for detecting current flowing to said driving means when the rotation of said DC motor is driven, and when said DC motor is in an inoperative state before said DC motor begins to rotate;

wherein said control means stops operation of said driving means and causes said warning means to give warning when said driving means has continued to operate over a predetermined time period while the current detected by said current detecting means falls within a range between a first predetermined value and a second predetermined value.

6. An automotive passenger restraint and protection apparatus as claimed in claim 5, wherein said range between said first predetermined value and said second predetermined is a range that can be assumed when said driving means runs idle while it is functioning normally.