JPH0374235A - Malexplosion recording device for air bag device - Google Patents

Abstract

PURPOSE:To obtain a recording device having high antinoise property against electromagnetic noise and surely recording by connecting a current recording means constituted so that a magnetic steel piece is inserted and fitted to a coil flawing current to an activation means through itself, on a current route of feeding current to the activation means. CONSTITUTION:When acceleration and deceleration at collision of an automobile are detected with acceleration sensors 7, 8, armatures 7a, 8a are closed, electric charge in a back up condenser 4 charged from the battery 1 loaded on a vehicle is quickly discharged, and a squib 11 is ignited to expand and develop an air bag. At this time, a magnetic steel piece 17 is magnetized by current in a coil 15 and residual magnetic flux is memorized. This magnetic steel piece 17 is taken out and inserted and fitted into a magnetism detector to read out residual magnetism, and normal ignition of the squib 11 is detected. In the case of collision of an automobile after the squib 11 is exploded in error by static electricity or mechanical shock, no current is fed to the coil 15, residual magnetism can not be detected even at inserting the magnetic steel piece 17 into the magnetism detector, hereby explosion in error of the squib 11 is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an accidental explosion recording device in an airbag device mounted on a high-speed moving object such as an automobile.

[Prior Art] An airbag device is installed in the front of an occupant's seat, such as the driver's seat, of a high-speed moving body such as an automobile, and activates an airbag activation detonator called a squib in the event of a collision of the automobile. This inflates and deploys the airbag to protect the occupant's body by mitigating the impact force caused by a collision to the front of the occupant's seat, but the activation device is activated by static electricity or mechanical shock. Because there is a possibility of accidental detonation,
Based on the recording results of the recording device, it is determined and monitored whether the detonator detonated due to normal ignition or erroneous detonation.

The bottom of the tank of this type of device that has already been proposed is explained with reference to FIG. A diode that charges the backup capacitor (4) with the current of (5) is the backup capacitor (
Acceleration sensor (7) that detects the charged charge of 4) and the deceleration acceleration at the time of collision and closes the contacts (7a) and (8a).
, (8), and these elements form a power supply circuit. In the current path through which the discharge current from the backup capacitor (4) is supplied, there is a squib (11) made of a heating wire with an internal resistance of several ohms, which ignites the explosive for expanding and deploying the airbag by supplying the discharge current. On the other hand, a magnetic core (9>) with a Hall element (10) inserted into the magnetic air gap is inserted.The output voltage of the Hall element (10) is connected to the amplifier (12).
When the current is amplified by and exceeds a certain current value sufficient to start the squib (11), the current detection is recorded in the storage device (13) consisting of a latching relay or a semiconductor memory. Note that symbols (7b), (8b)
are the contacts (7a) of the acceleration sensors (7) and (8), (
8a) With the parallel resistors, when the contacts (7a) and (8a) are opened, a minute current is supplied to the squib (11) to the extent that it does not affect the deployment of the airbag.

Next, to explain the operation, when a car collides, the deceleration is detected and the contacts (7a) and (8a) of the acceleration sensors (7) and (8) are closed, which causes the charge in the backup capacitor (4) to be closed. is a diode (5)
is rapidly discharged to the contact (7a) of the acceleration sensor (7), the squib (11), and the contact (8a) of the acceleration sensor (8), igniting the squib (11) and firing the airbag (11) (not shown). While expanding and deploying, the core (9)
The magnetic flux induced in the Hall element (1o) is applied to the Hall element (1o), its output is amplified by the amplifier (12), and when a current of a certain value or more is detected, this is stored in the storage device (13). By reading this stored content with an appropriate reading means, it is determined that the squib (11) has ignited normally. If the squib (11) accidentally explodes due to static electricity or mechanical shock, the memory will not be stored because the starting current will not flow, but even if a car crashes after this, the squib (11) will have already exploded due to the accidental explosion. Since the circuit is open, nothing will be recorded in the storage device (13). Therefore,
Even if the data is read from the storage device (13), no stored result is obtained, and it can be determined that there has been an erroneous explosion.

[Problem to be Solved by the Invention] The above-mentioned device is related to a configuration in which an electronic recording circuit consisting of an amplifier, a latching relay, or a memory circuit formed by a semiconductor memory is provided. It is sensitive to the effects of electromagnetic noise, which increases the possibility of erroneous recording, resulting in unreliable recording results.

The present invention has been made in order to solve the above-mentioned problems, and its purpose is to have high noise resistance against electromagnetic noise from peripheral devices, and to provide a highly reliable system that enables reliable recording. An object of the present invention is to provide an accidental explosion recording device for an airbag device.

[Means for Solving the Problems] The accidental explosion recording device in the airbag device of the present invention is characterized by an acceleration sensor that closes contacts and supplies power current in response to deceleration acceleration at the time of a collision; In an airbag device, a magnetic steel piece is inserted into a coil through which current supplied to the activation means flows, in a current path that supplies current to the activation means. The device is characterized in that a current recording means formed by an electric current recording means is connected thereto.

[Operation] When the deceleration and acceleration of the vehicle at the time of a collision is detected, and the contact of the acceleration sensor closes, the supply current from the power supply circuit is sent to the starting means via the contact of the acceleration sensor, and the current is applied to the coil at this time. Magnetic memory is performed in the magnetic steel piece inserted into the coil by the magnetic field generated by the flowing current.

[Embodiment] Hereinafter, a detailed description of an embodiment of the apparatus of the present invention will be given based on the accompanying drawings.

FIG. 1 shows a circuit device of one embodiment of the device of the present invention, and the symbols (1) to (8) and (11) in the figure have the same configuration and the same function as those already explained. from,
The details are omitted. Code 15) is the acceleration sensor (7
), in the current path between the squib (11> and the acceleration sensor <8), the coil is connected to the input side of the squib (11) and is wound around the bobbin (■6>).
A ferromagnetic bar-shaped magnetic steel piece (17>) made of a material with a large residual magnetic flux is inserted into the bobbin (16) in a demagnetized state, and this magnetic steel piece (17>
and a coil (15) constitute a current recording means.The magnetic steel piece (17) is hysteresis created by applying a magnetizing current from a demagnetized state to excitation, demagnetization, and re-excitation as shown in Fig. 2. It is a ferromagnetic material that draws a loop, and when a starting current flows through the coil (15), a magnetic field Hl due to the starting current is generated.
As a result, the magnetic steel piece (17) is magnetized and memorized up to the magnetic flux B1. Then, the magnetic steel piece (17) is taken out from the bobbin (16>) and inserted into a well-known magnetic detection needle (not shown), and the residual magnetic flux B1 is detected from the deflection angle of the magnetic needle of the magnetic detection needle. It is possible to detect that something has happened.

When reusing the magnetic steel piece (17
).

Next, to explain the operation of the device of the present invention, when the acceleration sensors (7) and (8) detect deceleration and acceleration at the time of a collision of a car, the contact pieces (7a) and (8a) are closed, and the Electric charge stored in the backup capacitor <4> from the battery (1) via the ignition switch (2), diode (3), and resistor (6) is transferred via the diode (5) to the contact point of the acceleration sensor (7). (7a)
, the coil (15), the squib (11), and the contact point (8a) of the acceleration sensor (8) are rapidly discharged, thereby causing the squib (11) to ignite and inflate and deploy an airbag (not shown). At this time, the magnetic steel piece (17) is magnetized by the current flowing through the coil (15) as shown in FIG. 2, and the residual magnetic flux B1 is memorized. This magnetic steel piece (17) is attached to the bobbin (16).
, and insert it into a magnetic probe (not shown) to detect residual magnetization B.
can be read and it can be detected that the squib (11) has normally ignited. Next, if a car crashes after the squib (11) accidentally explodes due to static electricity or mechanical shock, no current will flow through the coil (15) and the magnetic steel piece (17) will not be magnetized. Therefore, even if the magnetic steel piece (17) is inserted into the magnetic probe, residual magnetization is not detected, and it is thus detected that the squib (11) has erroneously detonated. Further, even if electromagnetic noise is received from a peripheral device, the magnetization caused by the noise is much lower than the magnetization caused by the current during normal ignition, so there is no problem in determining whether or not there is normal ignition.

[Effects of the Invention] As described above, according to the present invention, a current recording means formed by inserting a magnetic steel piece into a coil through which a current supplied to the starting means flows is connected to a current path that supplies current to the starting means. With this structure, the operating current of the starting means can be stored electromagnetically without any electronic processing, and therefore can be stored reliably without being affected by electromagnetic noise from peripheral devices. This makes it possible to improve noise resistance, thereby significantly improving the reliability of recording results. Moreover, since it has a simple configuration in which magnetic steel pieces are inserted into the coil, the number of parts can be significantly reduced, and the cost can be reduced.

[Brief explanation of drawings]

Fig. 1 is a circuit configuration diagram showing an embodiment of the device of the present invention, Fig. 2 is a diagram showing the magnetic properties of a magnetic steel piece applied to an embodiment of the device of the present invention, and Fig. 3 is a diagram of the conventional device. FIG. 3 is a circuit configuration diagram. In the drawing (1)...Vehicle battery, (2)...Ignition switch, (3), (5)...Diode, (4)
Backup capacitor, (7), (8)...
Acceleration sensor, (7a), (8a)...Acceleration sensor contact, (15)...Coil, (■6)...Bobbin, (17)...Magnetic steel piece. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent So Wa Michi Teru 0 Contents of the amendment to the procedural amendment October 12, 2015 (1) Figure 3 of the drawings is amended as shown in the attached sheet.

Claims (1)

[Scope of Claims] An airbag device comprising: an acceleration sensor that supplies a power supply current in response to deceleration acceleration in the event of a collision; and activation means that inflates and deploys an airbag using the current supplied from the acceleration sensor; An airbag device characterized in that a current recording means formed by inserting a piece of magnetic steel into a coil through which a current supplied to the starting means flows is connected to a current path for supplying current to the means. Accidental explosion recording device.