JP2598778Y2 - Actuator of occupant protection system - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operating device for a vehicle occupant protection system.

[0002]

2. Description of the Related Art A specific example of an operating device of a conventional occupant protection system will be described with reference to a circuit diagram of FIG. In FIG.
C is a backup capacitor for storing electricity supplied from a not-shown vehicle battery, S is a semiconductor switch connected in series to the backup capacitor C and connected to a collision determination circuit not shown, and R1 is a current limit connected in series to the semiconductor switch S. These resistors constitute the squib drive circuit 11 and are installed at appropriate places in the vehicle. A harness 10 connects the squib 3 of the airbag module 12 installed at the center of the handle to the current limiting resistor R1 of the squib drive circuit 11. 2
Is a coil spring that is disposed in place of the slip ring on the rotating portion of the handle in the harness and enables the handle to rotate while being connected by a wire. The airbag module 12 includes an occupant protection system 4 such as an airbag,
It has a gas generator (not shown) for operating the gas generator, and a squib (igniter) built in the gas generator and having an ignition charge (ignition charge) 9 and a bridge wire 8 for heating the ignition charge 9. ing. The electric bridge 8 is connected to the harness 12. The resistance of the bridge wire 8 is 2 Ω, and the resistance of the harness 10 is 2 to 3 Ω due to the need for a fixed length and the coil spring 2 provided on the way. The resistance of R1 is 1.1Ω
It has become.

When a collision detection circuit (not shown) detects a collision, the semiconductor switch S is turned on, and the voltage of the backup capacitor C (24
V) is applied, a current i flows through the electric bridge wire 8, and the ignition charge 9 is heated by the Joule heat due to its electric resistance and ignites. This firing activates the gas generator to operate the occupant protection device such as the airbag 4. The current i is set to 1.75A.

[0004]

The operating device 1 of the above-mentioned occupant protection system is required to be reduced in size because it is mounted on an automobile having a limited installation space. However, it is about to become business card box size and match box size soon. The backup capacitor C occupies the largest volume in the operating device 1. Therefore, in order to reduce the size of the operating device, it is necessary to reduce the size of the backup capacitor C.

The present invention has been made in view of such problems of the prior art, and an object of the present invention is to reduce the size of a backup capacitor to reduce the size of an occupant protection system operating device. Is to provide.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an occupant protection system operating device according to the present invention comprises a backup capacitor for storing electricity supplied from a vehicle-mounted battery, an ignition powder, and a backup capacitor. An ignition device, which is connected via required wiring such as a harness, and converts the electric power into heat by an electric resistance when energized to ignite the ignition explosive. In the occupant protection system operating device for operating an occupant protection system such as an airbag, the electric resistance of the electric bridge line is set to 10Ω to 30Ω.

[0007]

The electric resistance of the bridge wire of the squib is increased from 10 to 30 Ω as compared with the prior art, so that the flowing current is reduced, the loss due to the harness and the like is reduced, and the capacity of the backup capacitor can be reduced.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing a configuration of an operating device of the occupant protection system of the present invention, FIG. 2 is a component arrangement diagram of an operating device of the occupant protection system of FIG. 1, and FIG. FIG. 4 is a cross-sectional view showing the structure of a squib to be obtained, and FIG. 4 is a view taken along an arrow A of FIG.

First, the overall configuration will be described with reference to FIGS. In FIG. 1, the electric resistance of the squib was set to 25Ω, and the conduction current was set to 0.5 A. The current limiting resistor R11 is appropriately set. The rest is the same as the conventional one shown in FIG. In the component layout diagram of FIG.
C3 (C11) indicates a backup capacitor. What was conventionally large as shown by the two-dot chain line C2 'is now downsized as shown as a result of the reduced capacity. Reference numeral 43 denotes a power circuit including a semiconductor switch or the like; 45, a signal processing circuit that outputs a start signal to the semiconductor switch;
S is an acceleration sensor that outputs an acceleration signal to the signal processing circuit, 42 is a power supply circuit that supplies a boosted voltage to the backup capacitors C1 to C3, SS is a safing sensor connected in series to the backup capacitors C1 to C3, 29
Is a connector to which a harness between the squib and the like is connected, and these components are arranged on the substrate 32. As a result of the miniaturization of the backup capacitors C1 to C3, the entire operation device is also miniaturized as illustrated.
Conventionally, in squib diagnosis, as shown in FIG. 5, it is necessary to determine the normality of a 2 Ω squib (wire bridge) resistance out of 3 to 4 Ω including a harness resistance.
Although the judgment was difficult, in this embodiment , 28Ω
It is only necessary to make a normal judgment of 25 Ω within the degree , and the judgment can be made with extremely high accuracy.

Next, a configuration example of the squib will be described with reference to FIG. In FIG. 3, the squib 13 is such that a cylindrical metal tube 22 is filled with the igniting agent 9 and a plug 24 for sealing the squib is provided at the base. On the upper surface of the plug body 25, the electric bridge line 25 is buried in the ignition charge 9, and
The lead wires 25a and 25b penetrate the plug 24 and protrude to the outside. The portion of the electric bridge line 25 buried in the igniting charge 9 was conventionally a straight line as shown by a dotted line.
It is wound in a coil shape as shown by the solid line, thereby increasing the resistance value by increasing the length of the wire within a limited space and simultaneously supplying power to the ignition charge 9 intensively. Making it possible. With such a three-dimensional coil shape, the length of the line can be made longer than in a planar case. Note that a nichrome wire is used as a material for the electric bridge wire. A fragile portion is provided on the upper surface 2a of the tube body 22, and the igniting agent 9 is ignited by energizing heating of the electric bridge wire 25, the fragile portion is broken, and a flame is ejected upward (in the direction of the arrow 23). Thus, a transfer charge of a gas generator (not shown) is ignited.

FIG. 4 shows another embodiment of the electric bridge line.
It is an arrow view. In FIG. 4A, the portion of the electric bridge line 35 that comes into contact with the igniting agent is formed in a planar wavy shape along the upper surface of the plug 24. In this way, when the shape is planar, the shape is stably maintained when the ignition charge is ignited. FIG.
In (b), the electric bridge line 45 has a portion that comes into contact with the igniting agent formed in a spiral shape in a plane along the upper surface of the plug 24,
The terminal portion 45a from the center is formed so as to three-dimensionally intersect with the spiral portion in the upper part of the drawing. in this way,
In the case of the spiral shape, the spiral shape has a high space factor, so that the length of the line can be made longer.

As described above, when the portion of the electric wire that comes into contact with the igniting agent has a planar shape, it can be formed on a printed circuit board. In this case, the line interval can be made smaller, the line length can be made longer, and the resistance value can be easily increased. In addition, the risk of disconnection or short circuit at the time of ignition of the ignition agent is reduced.

[0013] The shape of the electric bridge wire shown in FIGS. 3 and 4 is merely an example, and the portion that comes into contact with or embeds the igniting agent is formed in a bent or wound shape, so that it is more difficult than a conventional straight wire. It can be used if it gets longer. Further, in order to increase the resistance value of the electric bridge wire, a material having higher resistivity can be used instead of the above-described nichrome wire, and the wire can be made thinner instead of making the wire longer.

[0014]

As described above, the operating device of the occupant protection system according to the present invention reduces the electric resistance of the squib's bridge line by 10%.
Since the resistance is increased from Ω to 30Ω, the size of the backup capacitor can be reduced to reduce the size, and the squib diagnosis can be facilitated. And as a result of reducing the size of the backup capacitor, it is possible to reduce the size of the actuator.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of an operating device of the occupant protection system of the present invention.

FIG. 2 is a component layout of the operating device of the occupant protection system of the present invention.

FIG. 3 is a cross-sectional view showing a structure of a squib used in the operating device of the occupant protection system of the present invention.

FIG. 4 is a diagram showing another embodiment of the electric bridge line.

FIG. 5 is a circuit diagram showing a configuration of an operating device of a conventional occupant protection system.

[Explanation of symbols]

 C11 (C1 to C3) Backup capacitor 4 Occupant protection system such as airbag 9 Ignition powder (ignition charge) 10 Harness 11 Actuator of occupant protection system 13 Squib (igniter) 25 Electric bridge line

Claims (3)

(57) [Scope of request for utility model registration] A squib drive circuit having a backup capacitor for storing electricity supplied from an on-vehicle battery; an explosive for ignition; scan and a bridge wire to ignite
And Kuibu, for connecting the said squib drive circuit squib
An operating device of an occupant protection system for activating an occupant protection system such as an airbag by firing the explosive for ignition, wherein an electric resistance of the electric bridge line is in a range of 10Ω to 30Ω . In
The resistance of the squib drive circuit and the squib drive circuit.
Required harness etc. to connect road and squib
An occupant protection system operating device, characterized in that the resistance of the occupant protection system is greater than the combined resistance of the wiring . 2. The operating device of the occupant protection system according to claim 1, wherein a portion of the electric bridge line which is in contact with or embedded in the explosive for ignition is formed in a bent or wound shape. 3. The squib drive circuit and the squib
The required wiring, such as a harness for connecting
3. The riding device according to claim 1, further comprising a spring.
Actuator of personnel protection system.