JP4031258B2 - Air bag system igniter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an igniter for an airbag system used in an airbag system using a bus system, and an operation control method for the airbag system using the igniter.
[0002]
[Prior art and problems to be solved by the invention]
An airbag system for protecting an occupant from an impact at the time of a vehicle collision is indispensable. However, the weight reduction of the airbag system is demanded from the demand for weight reduction of the entire vehicle. Recently, there has been a tendency for the number and type of airbags to increase, such as for driver seats, passenger seats, rear seats, and side collisions, so the demand for weight reduction of airbag systems has become greater. ing.
[0003]
In the current airbag system, an electronic control unit (ECU) connected to a power source (vehicle battery) and an impact detection sensor and individual gas generators (a gas generator and an airbag are installed in a module case). Are connected individually). FIG. 13 shows an image of the connection state between this ECU and each gas generator.
[0004]
As shown in FIG. 13, the ECU and the igniters of the individual gas generators (FIG. 14) are always connected by two conductors. Therefore, twice as many conductors as the total number of igniters are required. A large number of conductors account for a large portion of the weight increase in airbag systems. And, because of restrictions in assembling vehicle parts, the ECU and individual gas generators are not connected only by conductors, but are connected by connecting a plurality of conductors via a plurality of connectors. Further, the increase in weight due to the connectors and the increase in cost due to the increase in the number of connectors are also serious problems. Furthermore, an increase in the capacity (weight) of the ECU due to an increase in the capacity (weight) of the capacitor built into the ECU as a backup power supply for operating all these igniters (when the wiring between the power supply and the ECU is disconnected) large.
[0005]
Thus, attempts have been made to reduce the conductor weight required for connection between the ECU and each gas generator by using the bus system in an airbag system. An image of an airbag system using this bus system is shown in FIG.
[0006]
As shown in FIG. 1, a bus line composed of a plurality of annular wires passing through the ECU is provided, and each gas generator is connected to the bus line via two conductors (in some cases, three or more), and an airbag is provided. The system is configured. In the case of the airbag system as shown in FIG. 1, in order to operate only the necessary gas generators in response to the collision situation of the vehicle, each gas generator receives an information transmission from the ECU. A circuit and a capacitor are installed to supply the current that activates the igniter. When the bus system is used, although the total number of capacitors increases, the capacity and weight of each capacitor is reduced because the ECU and the igniters are distributed, so the backup in the airbag system of FIG. The weight of the capacitor is significantly reduced compared to the weight of the condenser, and when combined with a significant reduction in the amount of conductors used, the overall system will lead to a significant weight reduction. . As prior art using a bus system, Japanese Patent Laid-Open No. 2000-241098, Japanese Translation of PCT International Publication No. 2000-513799 and Japanese Patent No. 2707250 are known.
[0007]
The present invention introduces a bus system into an air bag system to achieve a significant weight reduction of the entire system, and can ensure the reliability and speed of operation similar to those of the conventional air bag, thereby obtaining high reliability. It is an object of the present invention to provide a system igniter and an operation control method for an airbag system using the igniter.
[0008]
[Means for Solving the Problems]
(1) First solving means
According to a first aspect of the present invention, there is provided an electronic control unit connected to a power source and an impact detection sensor, and a plurality of gas generators and airbags connected to the electronic control unit. 1 or 2 or more igniters incorporated in the plurality of gas generators, used in an airbag system having a plurality of module cases,
The airbag system is provided with a bus line composed of a plurality of annular wires that pass through the electronic control unit and supply and transmit current and required information, and a plurality of conductors branch from the bus line at a required portion. Individual gas generators housed in the module case are operatively connected,
One or more igniters incorporated in the gas generator are electric igniters with a heat generating part and an igniting agent in contact with the heat generating part, and the igniter and the bus line are connected by a plurality of conductors. An integrated circuit in which information for expressing a required function and a capacitor is recorded is installed in the igniter, and an igniter ignition current is supplied to one or more igniters via the igniter capacitor. An igniter for an airbag system is provided.
[0009]
The annular wire forming the bus line and the conductor connecting the bus line and the gas generator can be two, three, or four or more, but two are preferable from the viewpoint of simplifying the entire system.
[0010]
The ignition agent is not particularly limited, and a combination of a metal or the like and an oxidizing agent such as perchlorate is preferable, and a combination of a metal such as zirconium, titanium, or hafnium and a perchlorate is more preferable, and in particular, zirconium and perchlorate. A mixture with potassium acid (ZPP) is preferred. It is desirable that the ZPP is granular and the particle diameters of zirconium and potassium perchlorate are adjusted.
[0011]
The capacitance of the capacitor is preferably 24 μF or less, more preferably 12 μF or less, and even more preferably 6 μF or less.
[0012]
In the air bag system using the air bag system igniter according to the invention, the current for igniting ignition is supplied to one or more igniters via the capacitor in the igniter, and the current supply time is as follows. And a time from when a current value corresponding to 5% of the maximum current value is reached to a time when it decreases to a current value corresponding to 5% of the maximum current value, and so that the time is within 500 μsec. It is desirable. Here, the maximum current value in the current supply time is a current value sufficient to ignite the igniting agent. The current supply time is preferably within 200 μsec, more preferably within 100 μsec. The current value at this time varies depending on the resistance value of the heat generating portion of the igniter, and is determined by the presence or absence of the discharge waveform conversion circuit, the configuration of the discharge waveform conversion circuit, the particle size of the ignition agent, the shape of the heat generating portion, and the like.
[0013]
In the case of a conventional airbag system, the current for operating the igniter is about 2 msec at 1.2 A from a relatively large capacity power source (battery), that is, a relatively low current is passed for a long time. The current waveform (vertical axis is current value (A), horizontal axis is time (μsec)) is rectangular.
[0014]
However, in the above invention, since the current for operating the igniter is supplied from a capacitor having a relatively small capacity, the ignition agent is ignited more smoothly by flowing it at a relatively high current for a short time, and the ignition energy itself is reduced. It is desirable because it is possible. When discharge is started when the waveform of the ignition current at this time (current value (A) on the vertical axis and time (μsec) on the horizontal axis) is time t = 0, the following formula (I):
i (t) = (V ₀ / R) × e ^{-t / CR} (I)
(Where v ₀ Is the capacitor charging voltage (V), R is the circuit resistance (Ω), C is the capacitor capacity (μF), t is the time (μsec), and i is the current (A). ).
[0015]
In the case of the discharge waveform represented by the formula (I), the current value becomes larger than that of the conventional rectangular waveform, but the energization time is shortened, so that the ignition energy itself is greatly reduced.
[0016]
In the above invention, the time during which a stable current supply is maintained after reaching a desired current value is defined as t (μsec), and the supply of current for heating the heat generating portion is stopped from the waveform start time. The relationship between t and T (t / T) is in the range of 0 ≦ t / T <0.2 or 0.5 <t / T <1 where T is the time until T (μsec) Is preferred.
[0017]
In the case of 0 ≦ t / T <0.2, it is close to the discharge waveform (waveform close to a triangle) when the electricity stored in the capacitor is directly applied to the heat generating part, and in the case of 0.5 <t / T <1 Is close to a waveform (waveform close to a trapezoid) when the discharge waveform is converted through a discharge waveform conversion circuit or the like that converts the waveform of electricity stored in the capacitor into a signal waveform of a current for ignition agent ignition.
[0018]
In the above-described invention, an integrated circuit provided with a capacitor and a required function can be installed for each igniter, and it is preferable that a discharge waveform conversion circuit is further included. This discharge waveform conversion circuit has a function of converting the discharge waveform represented by the formula (I) into a triangular wave or a trapezoidal wave. A coil can be interposed in the connection circuit, and the discharge waveform conversion circuit can also be provided in the integrated circuit from the viewpoint of simplifying the entire system.
[0019]
(2) Second and third solving means
The inventions according to claims 6 and 7 include, as means for solving the above problems, an electronic control unit connected to a power source and an impact detection sensor, and a plurality of gas generators and airbags connected to the electronic control unit. An igniter incorporated in one or more of the plurality of gas generators for use in an airbag system having a plurality of module cases accommodated;
The airbag system is provided with a bus line composed of a plurality of annular wires that pass through the electronic control unit and supply and transmit current and required information, and a plurality of conductors branch from the bus line at a required portion. Individual gas generators housed in the module case are operatively connected,
One or more igniters incorporated in the gas generator are electric igniters equipped with a heat generating part and an igniting agent in contact with the heat generating part, and the igniter and the bus line are connected by a plurality of conductors. ,
For each igniter, a capacitor, an integrated circuit in which information for expressing a required function is recorded, and a heat generating unit are installed on the same substrate, and the substrate is suspended,
There is provided an igniter for an air bag system in which at least a capacitor and an integrated circuit in the substrate are not in contact with an igniting agent, and a current for igniting agent ignition is supplied to the igniter via a capacitor in the igniter. .
[0020]
As another means for solving the above problems, the present invention accommodates an electronic control unit connected to a power source and an impact detection sensor, and a plurality of gas generators and airbags connected to the electronic control unit. An igniter that is used in an air bag system having a plurality of module cases and that is incorporated in one or more of the plurality of gas generators;
The airbag system is provided with a bus line composed of a plurality of annular wires that pass through the electronic control unit and supply and transmit current and required information, and a plurality of conductors branch from the bus line at a required portion. Individual gas generators housed in the module case are operatively connected,
One or more igniters incorporated in the gas generator are electric igniters equipped with a heat generating part and an igniting agent in contact with the heat generating part, and the igniter and the bus line are connected by a plurality of conductors. ,
Each igniter has a capacitor installed on the same substrate and an integrated circuit on which information for expressing the required function is recorded, and the substrate is vertically suspended,
Further, the substrate and the igniting agent are partitioned vertically by a header for supporting a conductive member that supplies and transmits current between the substrate and the heat generating portion, and the substrate is provided below the header, and the heat generating portion. Is provided above the header,
Provided is an igniter for an air bag system in which a current for igniting ignition is supplied to one or more igniters via a capacitor in the igniter. In addition, as long as the heat generating part is provided above the header, the heat generating part may be provided on the header surface or may be provided away from the header surface.
[0021]
In each of the above inventions, the annular wire forming the bus line, and the conductor connecting the bus line and the gas generator can be two, three or four or more, but from the viewpoint of simplifying the entire system. Two are preferred.
[0022]
In each of the above inventions, the igniting agent is not particularly limited, preferably a combination of a metal or the like and an oxidizing agent such as perchlorate, more preferably a combination of a metal such as zirconium, titanium, or hafnium and a perchlorate, In particular, a mixture of zirconium and potassium perchlorate (ZPP) is preferable. It is desirable that the ZPP is granular and the particle diameters of zirconium and potassium perchlorate are adjusted.
[0023]
In each of the above inventions, the capacitance of the capacitor is preferably 24 μF or less, more preferably 12 μF or less, and even more preferably 6 μF or less.
[0024]
In each of the above-mentioned inventions, an integrated circuit to which a capacitor and a required function are provided can be installed for each igniter of each gas generator, and it is preferable that a discharge waveform conversion circuit is further included.
[0025]
In each of the above inventions, it is possible to have a structure in which an integrated circuit (and a discharge waveform conversion circuit if necessary) is provided on one side of the substrate and a capacitor (and a discharge waveform conversion circuit if necessary) is provided on the other side. Although the heat generating portion can be provided on either surface, it is desirable to provide the heat generating portion on the same surface side as the integrated circuit because the circuit can be easily formed (soldering operation). Further, when providing the discharge waveform conversion circuit, it is desirable to provide it in the integrated circuit from the viewpoint of simplifying the entire system.
[0026]
In each of the above inventions, the board is fitted through the header that forms the ignition agent holding space together with the cup member that holds the ignition agent, the capacitor and the integrated circuit are located below the header, and the heat generating part is located above the header It can be made the structure which protrudes in contact with the ignition agent.
[0027]
When the heat generating part is provided on the header, the heat generating wire is attached on the header by welding; the metal foil is attached to an insulating substrate made of aluminum, glass, epoxy resin, phenol resin, polyimide, etc. having an oxide film. Then, a method of forming by etching; a method of forming by depositing a conductive material on a masked insulating substrate; a method of printing a conductive material on the insulating substrate, and the like are applied.
[0028]
Thus, by providing the integrated circuit and the capacitor separately on both sides of the substrate, it is possible to make it more compact than the case where it is provided on one side. In addition, since the integrated circuit and the capacitor do not come into contact with the igniting agent by providing the igniting agent above the header and the substrate below the header, contamination of the capacitor and the integrated circuit by the igniting agent is prevented. There is no risk of malfunction.
[0029]
In each of the above inventions, an integrated circuit and a capacitor (and a discharge waveform conversion circuit if necessary) can be provided on one side of the substrate, and the heat generating part may be provided on either side, It is desirable to be on the same side as the integrated circuit and the capacitor. This discharge waveform conversion circuit has a function of converting a discharge waveform represented by the following formula (I) into a triangular wave or a trapezoidal wave.
[0030]
In each of the above inventions, the portion excluding the heat generating portion of the substrate is sealed with a glass fiber-containing thermoplastic resin, a thermosetting resin such as epoxy resin, or an organic or inorganic insulating material such as glass, and the heat generating portion is ignited. When a substrate having such a structure is used, a header for supporting a pin serving as an intermediate member for supplying and transmitting current and necessary information to an integrated circuit and a capacitor is used. A structure in which a substrate exists above can be used.
[0031]
In such a structure, the capacitor and the integrated circuit are protected, and the capacitor and the integrated circuit are not in contact with the igniting agent, so that the capacitor and the integrated circuit are prevented from being contaminated by the igniting agent.
[0032]
In each of the above-described inventions, the integrated circuit, the heat generating portion, the connection portion between the capacitor and the bus line, and the heat generating portion of the igniter can be made of a conductor pattern formed on the substrate by etching. At this time, as shown in FIGS. 8 and 9, the conductor pattern forming the connection portion between the integrated circuit and the heat generating portion, the capacitor, and the bus line can have a total of six routes, two each. As the etching, wet etching, dry etching (plasma etching, sputter etching, reactive ion etching), photo etching, or the like can be applied.
[0033]
When such a conductor pattern is used, since the connection portion by soldering is reduced compared to the case where the integrated circuit, the heat generating portion and the capacitor are all connected by a conductor and the connection portion is soldered, the resistance value And the possibility of malfunction due to poor connection is reduced. Furthermore, by providing such a conductor pattern, wiring becomes easy, and manufacture becomes easy compared with the case where a bridge wire is provided as a heat generating part.
[0034]
In the first to third solving means, as an integrated circuit in which information for expressing a required function is recorded, (i) a function of detecting an abnormality of a heat generating part of an igniter in a gas generator, (ii) a plurality of (Iii) A function in which information for expressing one or more functions selected from a function for detecting a malfunction of a capacitor or two or more functions is recorded can be used. iv) It is preferable that a circuit for preventing the igniter from malfunctioning due to noise generated outside the igniter is provided in the igniter.
[0035]
The integrated circuit is provided with a basic function for operating an appropriate gas generator for occupant protection in response to a signal from the ECU according to the situation when the vehicle collides. In addition to the above, by adding the various functions described above, it is suitable for quality inspection of products at the time of shipment, improvement of workability at the time of assembly, improvement of safety at the time of practical use (during vehicle operation), etc. Become.
[0036]
(i) Function to detect abnormality of the heat generating part of the igniter in the gas generator
As one of the requirements for the gas generator to operate normally, a good contact state between the heat generating part of the igniter and the igniting agent is required (the heat generating part and the igniting agent are in a pressure contact state), for example, When there is a gap between the heat generating part and the igniting agent, it may be considered that the igniting agent does not ignite or an ignition delay occurs when the igniter is activated. Moreover, it is conceivable that the same problem occurs when the heat generating part is disconnected or is about to be disconnected. For this reason, if the information for detecting the malfunction is recorded in the integrated circuit, the defective product can be eliminated at the time of shipment of the product, and the abnormality is detected at the time of practical use (during driving of the vehicle). By doing so, it becomes possible to exchange quickly.
[0037]
The detection theory of abnormalities in the heat generation part (thermal transient test; ACMunger published in p. 461-478 of Progress of International Pyrotechnic Semina in July 1980) is as follows. When the contact state is good, the amount of heat generated by passing a constant current moves to the igniting agent, so the temperature of the heat generating part does not rise so much, while the contact state between the heat generating part and the igniting agent is poor. In this case, since the heat transfer is small, the temperature rise of the heat generating portion becomes higher than usual, so that the temperature change due to such a difference in the contact state is regarded as a resistance value change, and the temperature coefficient [r = r ₀ (1 + αΔT)] is used to determine the temperature of the heat generating portion, and a failure is detected. More specifically, after measuring the resistance r when a weak current i that causes a temperature rise that does not ignite the igniting agent is passed, a current I that is 10 to 15 times the current i is passed. (The temperature of the heat generating part is about 50 to 100 ° C., but the igniting agent is not ignited at this level.) By measuring the resistance R and comparing I and i and R and r, the temperature change of the heat generating part The resistance change due to the above is obtained by the voltage change, and such measurement information is recorded in the integrated circuit.
[0038]
(ii) Identification function for each gas generator
Various types of gas generators for airbags, such as for a driver seat, for a passenger seat, for a side (for side collision), for a curtain, etc. are practically used. For example, a side gas generator is used for a driver seat. Attach a total of four, one for each passenger seat and two rear seats. For this reason, different information is recorded in each integrated circuit of the side gas generator for each of the driver's seat, the passenger seat, and the two rear seats. If recorded at the time or before assembly, the igniters and gas generators have the same appearance, so if the same gas generator with different information recorded or the pre-assembly igniters have the same appearance It is necessary to store and transport them separately so that they are not complicated. Further, if the driver's seat for the passenger seat is mistakenly attached to the vehicle, when the operation information of the driver's seat airbag is issued from the ECU, a malfunction occurs in which the passenger seat airbag is inflated. It will be.
[0039]
Therefore, after recording the information to express the identification function for each gas generator, after assembling the gas generator (when the difference in gas generator can be recognized in appearance), incorporate the gas generator into the module case. After that (when the difference in the appearance of the module case can be recognized) or after it is installed in the vehicle, the gas generator can be stored, transported, managed, etc. It is prevented from occurring.
[0040]
The information for developing the identification function for each of the plurality of gas generators is preferably recorded after the gas generator is assembled, more preferably after the gas generator is assembled in the module case, and after being attached to the vehicle. It is more preferable to record.
[0041]
(iii) Capacitor detection function
Information for realizing the function of detecting a defect of the capacitor includes information for measuring the pulse response or dielectric loss tangent, and information for confirming the mounting state (soldering state) of the capacitor on the substrate.
[0042]
After being mounted on the vehicle, the capacitor deteriorates over time due to repeated charging and discharging. In By recording information capable of confirming the troubles in the integrated circuit, it is possible to promptly replace by detecting an abnormality in practical use (during vehicle operation). Also, by recording information for confirming the soldering state, defective products can be eliminated at the time of product shipment.
[0043]
(iv) Circuit that prevents the igniter from malfunctioning due to noise generated outside the igniter (noise countermeasure circuit)
For example, a large current flows when the vehicle's cell motor starts, but if no noise countermeasure circuit is added, noise generated by this current (noise that causes unpleasant abnormal noise when listening to radio) is transmitted from the vehicle body. If the noise is transmitted in this manner, there is a high possibility that the igniter will malfunction. Therefore, as a noise countermeasure circuit (a circuit that prevents the igniter from malfunctioning), a circuit that prevents current from flowing from the vehicle side to the igniter side, for example, a diode, a varistor (non-linear resistance element, etc.) is attached. Thus, the malfunction of the igniter described above is prevented.
[0044]
(4) Fourth and fifth solving means
According to a thirty-third aspect of the present invention, as another means for solving the above-described problems, in the airbag system igniter according to the present invention, when the plurality of gas generators include two or more igniters, Provided is an igniter for an air bag system in which two or more igniters share one capacitor and an integrated circuit in which information for expressing a required function is recorded.
[0045]
In this way, in each of two or more igniters, one capacitor and an integrated circuit in which information for expressing a required function is recorded, and further, ignition powder ignition accumulated in the capacitors for each igniter provided as necessary. By sharing the discharge waveform conversion circuit that converts the signal waveform of the current for use, the entire system can be further reduced in weight. The discharge waveform conversion circuit may be incorporated in an integrated circuit.
[0046]
The invention according to claim 31 is the air bag system igniter according to the invention as another means for solving the above-mentioned problem, wherein two or more igniters are provided for each of the plurality of gas generators. Each igniter has a capacitor and an integrated circuit in which information for expressing the required function is recorded, and further includes two pins for supplying and transmitting current and required information from the bus line to two or more igniters. An igniter for an airbag system having the present invention is provided.
[0047]
In the air bag system igniter in the first to fifth solutions described above, in order to further charge the capacitor, the capacitor charging current is rectified by rectifying the current out of the current for charging the capacitor from the bus line and the required information. It is preferable that a circuit having a function of flowing through a capacitor (hereinafter referred to as “rectifier circuit”) is provided in the integrated circuit, and the rectifier circuit includes a voltage for charging the rectified capacitor and a voltage applied to the bus line. It is preferable that a function of amplifying at least one of them exists.
[0048]
(5) Sixth solution means
The invention according to claim 34 is an operation control method of an airbag system using the above-described igniter for an airbag system as another means for solving the above-described problem, and the current supply time from the capacitor to the heat generating portion is as follows: An airbag system that controls the time from the time when a current value corresponding to 5% of the maximum current value is reached to the time when the current value decreases to 5% of the maximum current value is within 500 μsec. An operation control method is provided. Here, the maximum current value in the current supply time is a current value sufficient to ignite the igniting agent.
[0049]
In the case of a conventional airbag system, the current for operating the igniter is about 2 msec at 1.2 A from a relatively large capacity power source (battery), that is, a relatively low current is passed for a long time. The current waveform (vertical axis is current value (A), horizontal axis is time (μsec)) is rectangular.
[0050]
However, in the above invention, since the current for operating the igniter is supplied from a capacitor having a relatively small capacity, the ignition agent is ignited more smoothly by flowing it at a relatively high current for a short time, and the ignition energy itself is reduced. It is desirable because it is possible. When discharge is started when the waveform of the ignition current at this time (current value (A) on the vertical axis and time (μsec) on the horizontal axis) is time t = 0, the following formula (I):
i (t) = (V ₀ / R) × e ^{-t / CR} (I)
(Where v ₀ Is the capacitor charging voltage (V), R is the circuit resistance (Ω), C is the capacitor capacity (μF), t is the time (μsec), and i is the current (A). ).
[0051]
In the case of the discharge waveform represented by the formula (I), the current value becomes larger than that of the conventional rectangular waveform, but the energization time is shortened, so that the ignition energy itself is greatly reduced.
[0052]
In the above invention, the time during which a stable current supply is maintained after reaching a desired current value is defined as t (μsec), and the supply of current for heating the heat generating portion is stopped from the waveform start time. The relationship between t and T (t / T) is in the range of 0 ≦ t / T <0.2 or 0.5 <t / T <1 where T is the time until T (μsec) Is preferred.
[0053]
In the case of 0 ≦ t / T <0.2, it is close to the discharge waveform (waveform close to a triangle) when the electricity stored in the capacitor is directly applied to the heat generating part, and in the case of 0.5 <t / T <1 Is close to a waveform (waveform close to a trapezoid) when the discharge waveform is converted through a discharge waveform conversion circuit or the like that converts the waveform of electricity stored in the capacitor into a signal waveform of a current for ignition agent ignition.
[0054]
The current supply time is as described above, but is preferably within 200 μsec, more preferably within 100 μsec. The current value at this time varies depending on the resistance value of the heat generating portion of the igniter, and is determined by the presence or absence of the discharge waveform conversion circuit, the configuration of the discharge waveform conversion circuit, the particle size of the ignition agent, the shape of the heat generating portion, and the like.
[0055]
(6) Seventh solution
The invention according to claim 37 is an operation control method of an airbag system using the above-described igniter for an airbag system as another means for solving the above problem, and supplies a current to the heat generating portion as an ignition pulse, Provided is an operation control method for an airbag system that supplies current so that the width of the ignition pulse is 20 to 500 μsec.
[0056]
In the case of a conventional airbag system, the current for operating the igniter is about 2 msec at 1.2 A from the power source (battery), that is, a relatively low current is passed for a long time. Pulse) [vertical axis is current value (A), horizontal axis is time (μsec)] is rectangular.
[0057]
Therefore, in the above invention, the current is supplied so that the current is relatively high and the time is short, that is, the width of the ignition pulse at that time is 20 to 500 μsec, preferably 30 to 200 μsec, more preferably 40 to 100 μsec. . As a result, since the amount of ignition energy required to operate each igniter can be reduced, the amount of ignition energy required for the entire igniter, that is, the entire airbag system can be reduced. For this reason, the capacity | capacitance of the capacitor | condenser for backup power supplies incorporated in ECU can be made small, Therefore ECU itself can also be made small.
[0058]
In the said invention, it is preferable from a viewpoint of reducing an electric current amount to supply an electric current so that the width | variety of an ignition pulse may be 40-100 microseconds.
[0059]
DETAILED DESCRIPTION OF THE INVENTION
The igniter for an air bag system according to the present invention achieves weight reduction of the entire system by using a bus line, and achieves certainty of operation of the system by the above solution. Hereinafter, embodiments including the first to seventh solving means will be described. It should be noted that the order of the solution means and the order of the embodiments do not mean to coincide.
[0060]
(1) First embodiment
As shown in FIG. 1, the airbag system used in the igniter for an airbag system of the present invention uses bus lines 10 and 11 composed of two annular wires passing through the ECU. The ECU is connected to a power source (vehicle battery) (not shown) and an impact detection sensor. Further, the ECU is used as a backup when a conductor connecting the ECU and the power source is cut by an impact at the time of a vehicle collision. A capacitor is placed. In the air bag system igniter according to the present invention, a capacitor is arranged for each gas generator (igniter). Therefore, the backup capacitor may have a small capacity (that is, light weight). The capacitor for backup in the conventional airbag system shown in FIG. 13 has a large capacity because it is necessary to operate all the gas generators by one when the lead wire is disconnected between the battery and the ECU. It will be a thing.
[0061]
The bus lines 10 and 11 and the gas generators in the required number of module cases (illustrated by black circles. A gas generator and an air bag are accommodated in the case) mounted in the vehicle are two. The individual gas generators are operatively connected by (or possibly more than three) conductors.
[0062]
In the airbag system shown in FIG. 1, as the gas generator in the module case shown by a black circle, those shown in FIGS. 2 and 3 can be used according to the number of igniters. FIG. 2 is a radial sectional view of one single type (igniter 21) igniter, and FIG. 3 is a radial sectional view of two dual types (igniters 31, 32) of igniter. FIG.
[0063]
In the single type, the igniter 21 is provided with two (or three or more in some cases) pins 21 a and 21 b and is connected to the bus lines 10 and 11 via the connector 25.
[0064]
In the dual type, the igniter 31 is provided with two (or three or more in some cases) pins 31a and 31b, and the igniter 32 is provided with two (or three or more in some cases) pins 32a and 32b. And connected to the bus lines 10 and 11 via connectors 35 and 36, respectively.
[0065]
In the gas generator shown in FIGS. 2 and 3, for example, the igniter 21 and the igniters 31 and 32 may be those shown in FIG. 4. FIG. 4 is a longitudinal schematic cross-sectional view of the igniter. Since the igniter 21 and the igniters 31 and 32 can have the same structure, the igniter 21 will be described below.
[0066]
A heat generating part is provided on the glass header, filled with an igniting agent (for example, ZPP) so as to be in pressure contact with the heat generating part, and information for expressing a capacitor and a required function is recorded in the lower part. A substrate provided with an integrated circuit is provided. The integrated circuit, the heat generating portion, and the capacitor are each connected by two conductors, and the integrated circuit is further connected to the pins 21a and 21b via the conductors.
[0067]
In the integrated circuit, information is recorded so that at least a command from the ECU is received at the time of a vehicle collision and a necessary airbag can be inflated. Records information for expressing one or more functions selected from a function for detecting an abnormality in a heat generating part of an igniter in a generator, a function for identifying a plurality of gas generators, and a function for detecting a malfunction of a capacitor. Can be kept.
[0068]
The substrate on which the capacitor and the integrated circuit in the igniter 21 shown in FIG. 4 are installed can have the structure shown in the conceptual diagram of FIG. FIG. 6 shows pulse waveforms of the bus voltage, digital output, and charging voltage shown in FIG.
[0069]
A capacitor and an integrated circuit are installed on the board, and if necessary, a discharge waveform conversion circuit (shown in broken lines as a “waveform converter”) can be installed, and the discharge waveform conversion circuit itself is incorporated into the integrated circuit. You can also. The charging current to the capacitor is passed through the rectifier circuit.
[0070]
The integrated circuit and the capacitor on the substrate are connected to the bus lines 10 and 11 via pins 21a and 21b. The current and information supplied from the bus lines 10 and 11 are sent to the integrated circuit, then digitally output by an A / D converter (analog / digital converter), and sent to an MCU (Micro Computer Unit). In addition to sending instructions from the MCU to express charging control information, position identification information, disconnection detection information and resistance value change detection information of the heat generating part, the capacitor is charged, but in order to heat the heat generating part Not used.
[0071]
A varistor (nonlinear resistance element) is arranged between the circuits connecting the MCU and the heat generating part as noise prevention means. The Therefore, the igniter does not malfunction due to noise generated outside the igniter.
[0072]
The heat generating part is in contact with the igniting agent and generates heat by supplying current only from the capacitor to ignite the igniting agent.
[0073]
Next, the operation of the air bag system igniter and the air bag system operation control method of the present invention will be described with reference to FIGS.
[0074]
When the vehicle is in a normal driving state, via the bus line, from the ECU to the gas generator (integrated circuit installed in the igniter), disconnection detection information, resistance value change detection information of the heat generation part, and capacitor malfunction Detection information and detection information on whether there is an igniter including the identification function necessary for gas generator operation (in order to properly operate the necessary gas generators such as the driver's seat and front passenger seat at the time of collision) The detection information on whether or not igniters having the same identification function are correctly arranged, and whether or not the igniters having the same identification function are duplicated are sent, and it is detected whether or not there is any abnormality. The And when there is an abnormality, it is possible to replace parts early by notifying with a warning lamp or the like that operates in cooperation with the airbag system, so that safety can be ensured. In addition, the capacitor of each igniter is charged from the power source.
[0075]
When a vehicle equipped with an igniter for an airbag system collides, information from the impact detection sensor is sent to the ECU, and the information from the ECU passes through the bus lines 10 and 11 and is used to ensure the safety of the passenger. Is sent to a gas generator (an integrated circuit installed in the igniter) that needs to be expanded.
[0076]
In response to this information, the time required for the required current from the capacitor to reach a predetermined time (from when the current value corresponding to 5% of the maximum current value is reached to when the current value decreases to 5% of the maximum current value). , Within 500 μsec), the heat generating part generates heat and ignites and burns the ignition agent. At this time, the current waveform is a discharge waveform represented by the formula (I) when the discharge is started at time t = 0. By this ignition combustion of the ignition charge, the transfer charge in FIG. 2 and FIG. 3 and further the gas generating agent are ignited and burned to generate gas, which is discharged from the gas discharge port, and is housed in the module case together with the gas generator. Inflate the airbag.
[0077]
(2) Second embodiment
The air bag system igniter according to the present embodiment is characterized by the structure, installation state, and the like of the substrate on which the integrated circuit and the like are installed.
[0078]
First, the substrate structure will be described. As shown in FIG. 5, the substrate is provided with a capacitor, an integrated circuit in which information for expressing a required function is recorded, and a heat generating portion, and these can be installed on one surface or both surfaces of the substrate.
[0079]
As shown in FIG. 7, an integrated circuit and a heat generating portion are provided on one surface side of the substrate, and a capacitor is provided on the other surface side. In this structure, the capacitor and the integrated circuit are connected by two conductors through two holes, and the integrated circuit and the heat generating part are connected by two conductors. The integrated circuit is also connected to the bus lines 10 and 11 through two conductors, igniter pins, and the like.
[0080]
As shown in FIG. 8, an integrated circuit, a heat generating part, and a capacitor can be installed on one side of the substrate. The integrated circuit, the capacitor, and the heat generating part are connected by two conductors, respectively. The bus lines 10 and 11 are also connected through conductors, igniter pins, and the like.
[0081]
As shown in FIG. 9, the integrated circuit and the connecting portion between the integrated circuit and the heat generating portion, the capacitor and the bus line, and the heat generating portion shown in FIGS. 7 and 8 are formed by a conductor pattern formed on the substrate by etching. Can do. By using such a conductor pattern by etching, the connection work between the elements is facilitated.
[0082]
As shown in FIG. 10, it is preferable to cover and seal the portion excluding the heat generating portion with an insulating material such as an epoxy resin because the sealing resin acts as a protective film for the integrated circuit and the capacitor. Although the substrate shown in FIG. 7 is used in FIG. 10, the substrate shown in FIG. 9 can also be used, and the substrate is provided in a standing state on a glass header.
[0083]
Next, the installation state of the substrate will be described with reference to FIG. The substrate used in FIG. 11 is the same as that shown in FIG. 10. In the drawing, the igniting agent covering the heat generating portion is deleted, and the insulating material sealing portion is partially cut away.
[0084]
As shown in FIG. 11, the igniter 21 (with a form different from that of FIG. 4) uses the substrate shown in FIG. 10, so the substrate is provided in a standing state on the header, excluding the heat generating part. The part is covered with an insulating material such as epoxy resin, and the heat generating part is in contact with the ignition agent. The contact surface between the bottom surface of the substrate and the head is fixed with an adhesive.
[0085]
In this way, by suspending the substrate on the header, the space capacity for installing the substrate can be reduced as compared with the case where the substrate is laid flat, so that the igniter itself can be downsized. Further, since the integrated circuit and the capacitor in the substrate excluding the heat generating portion are not in contact with the ignition agent, contamination or the like is prevented.
[0086]
In the igniter 21 shown in FIG. 4, the substrate and the igniter are partitioned vertically by a glass header for supporting the pins 21a and 21b, and a capacitor and an integrated circuit are installed on the same substrate. Is suspended below the header. The heat generating portion is provided above the header (the surface of the header), and the heat generating portion and the substrate are connected by a conductor (two pins 22a and 22b). The heat generating portion is formed by applying a method of welding and attaching a heat generating wire on the header.
[0087]
Also in the embodiment shown in FIG. 4, the integrated circuit, the capacitor, and the pins 21 a and 21 b can be connected by a conductive pattern by etching, and the heat generating portion and the integrated circuit can also be connected by a conductive pattern by etching.
[0088]
In this manner, by suspending the substrate under the header, the space capacity for installing the substrate can be reduced as compared with the case where the substrate is placed flat, so that the igniter itself can be downsized. Since the substrate and the igniting agent are not in contact with each other, contamination of the integrated circuit and the capacitor is prevented.
[0089]
The air bag system igniter of the second embodiment operates in the same manner as the air bag system igniter of the first embodiment.
[0090]
(3) Third to fifth embodiments
As shown in FIG. 5, the circuit board is provided with an integrated circuit in which information for expressing a function of detecting an abnormality of the heat generating part of the capacitor and the igniter is recorded, and the heat generating part of the igniter. Examples of the information include disconnection of the heat generating portion or poor contact between the heat generating portion and the ignition agent.
[0091]
By recording the above information on the integrated circuit, it is possible to quickly detect abnormalities such as disconnection or poor contact between the heat generating part and the igniting agent, so system replacement and occupant safety can be achieved by early replacement of parts. Can be increased.
[0092]
As shown in FIG. 5, the substrate is provided with a capacitor, an integrated circuit for recording information for realizing the identification function for each of the plurality of gas generators, and a heat generating portion of the igniter. It is desirable to record the information that causes the above identification function to be recorded after the gas generator is assembled, after the gas generator is assembled in the module case, or after being attached to the vehicle.
[0093]
By recording the identification function information on the integrated circuit in this way, management of product storage, transportation, etc. is facilitated, and malfunctions such as inflating an airbag different from the command from the ECU during practical use are prevented. Therefore, the reliability of the system and the safety of the passenger can be improved.
[0094]
As shown in FIG. 5, the substrate is provided with a capacitor, an integrated circuit in which information for expressing a function of detecting a defect of the capacitor is recorded, and a heat generating portion of the igniter. Examples of the information include information for measuring a pulse response or a dielectric loss tangent.
[0095]
By recording the above information on the integrated circuit, it is possible to quickly detect the malfunction of the capacitor. Therefore, the reliability of the system and the safety of the occupant can be improved by early replacement of parts.
[0096]
In the above third to fifth embodiments, the current required for the expression of each recorded information is supplied to the power source (vehicle battery) via the bus lines 10 and 11 and the two pins 21a and 21b of the igniter 21. ) To the integrated circuit, and a command for expressing the record information from the ECU is also transmitted to the integrated circuit through the same path as the current. The airbag system igniters of the third to fifth embodiments also operate in the same manner as the airbag system igniter of the first embodiment.
[0097]
(4) Sixth embodiment
FIG. 12 shows a gas generator having two igniters, in which two heat generating parts are one capacitor, an integrated circuit in which information for expressing a required function is recorded, and a discharge waveform conversion provided as necessary Share the circuit.
[0098]
When the gas generator has two igniters 31 and 32 as shown in FIG. 3, when only one of the igniters is operated due to the collision state of the vehicle, one of the igniters is operated first. In the case where the other is operated with a slight delay, or when two igniters are operated simultaneously, there are three possible modes of operation. The integrated circuit of the igniter in FIG. Information that can generate heat from the two heat generating portions is recorded in accordance with the contents of the command.
[0099]
The igniters 31 and 32 of the gas generator shown in FIG. 3 can have the structure shown in FIG. 5 or FIG.
[0100]
The air bag system igniter of the sixth embodiment also operates in the same manner as the air bag system igniter of the first embodiment, except that the air bag system igniter operates in accordance with the above-described three command contents.
[0101]
(5) Seventh embodiment
The operation control method of the airbag system incorporating the igniter for an airbag system of the present invention will be described with reference to FIGS.
[0102]
When the vehicle is in a normal running state, a weak current for detecting disconnection of the heat generating portion is sent from the MCU to the igniter of the gas generator, and it is detected whether there is any abnormality. And when there is an abnormality, it is possible to replace parts early by notifying with a warning lamp or the like that operates in cooperation with the airbag system, so that safety can be ensured. In addition, a current component is supplied for charging the capacitor together with required information from the bus line.
[0103]
When a vehicle equipped with an airbag system collides, information from the impact detection sensor is sent into the ECU, and further, an integrated circuit in the igniter develops a required function in response to the information sent from the ECU.
[0104]
As shown in FIG. 5 (or FIG. 12), the integrated circuit cuts off the current when the igniter is not required to operate. The A switch circuit (transistor) is provided for starting the supply of current when the igniter is activated. When the switch circuit is open, the current accumulated in the capacitor is not passed through the heat generating part.
[0105]
By sending a control pulse instructing opening / closing of the switch circuit from the MCU, the switch circuit is opened / closed. The control pulse transmission instruction to the pulse generator is sent from the MCU upon receiving a command from the impact detection sensor.
[0106]
For example, if a current pulse with a waveform width of 100 μsec is applied from the MCU, the switch circuit closes the switch for 100 μsec and flows the current from the capacitor as a pulse with a width of 100 μsec to the heat generating part of the igniter. That is, this switch circuit works to close the switch while a current (control pulse) is flowing through the circuit, like when a thyristor, MOS-FET, or bipolar transistor is used as the switch circuit. In this way, by applying a pulse having a predetermined time width (20 to 500 μsec) to the heat generating part of the igniter, the heat generating part is heated by the required ignition energy, and the ignition powder is ignited and burned.
[0107]
By the ignition and combustion of the ignition agent, the transfer agent in the gas generator of FIGS. 2 and 3 and further the gas generating agent are ignited and burned to generate gas, which is discharged from the gas discharge port, and the gas generator The airbag housed together is inflated.
[0108]
By using such an integrated circuit for an air bag system, the amount of current (ignition energy amount) required for normal operation of each igniter is reduced, so that the amount of current (ignition required for normal operation of the entire igniter) Energy amount) is also reduced, the capacity (ie, weight) of the capacitor for the backup power supply can be reduced, and the ECU itself can be reduced. For this reason, the weight of the whole airbag system can be reduced.
[0109]
An igniter for an airbag system according to the present invention includes an airbag inflator for a driver's seat, an airbag inflator for a passenger seat, an inflator for a side airbag, an inflator for a curtain, an inflator for a knee bolster, an inflator for an inflatable seat belt, and a tubular It can be applied as an igniter for various inflators (gas generators) such as a system inflator and a pretensioner inflator.
[0110]
【The invention's effect】
According to the air bag system igniter of the present invention, by using the bus system, the weight of the entire air bag system can be significantly reduced, and the same operation performance as that of the prior art can be ensured.
[Brief description of the drawings]
FIG. 1 is an image diagram of an airbag system to which an igniter for an airbag system of the present invention is applied.
FIG. 2 is a radial cross-sectional view of a gas generator (one igniter) incorporating the igniter for an airbag system of the present invention.
FIG. 3 is a sectional view in the radial direction of a gas generator (two igniters) incorporating the igniter for an airbag system of the present invention.
FIG. 4 is a longitudinal sectional view of an igniter for an airbag system according to the present invention.
FIG. 5 is a conceptual diagram of an igniter for an airbag system according to the present invention.
6 is a pulse waveform diagram of the bus voltage, digital output, and filling voltage shown in FIG.
7 is a plan view of both surfaces of a substrate (each element is disposed on both sides) installed in the air bag system igniter of the present invention. FIG.
FIG. 8 is a front view of a board (each element is arranged on one side) installed in the air bag system igniter of the present invention.
FIG. 9 is a front view of another embodiment of a substrate (each element is arranged on one side) installed in the air bag system igniter of the present invention.
FIG. 10 is a front view of the substrate installed in the air bag system igniter of the present invention sealed with an insulating material.
FIG. 11 is a longitudinal sectional view of another embodiment of an igniter for an airbag system according to the present invention.
FIG. 12 is a conceptual diagram of another embodiment of an igniter for an airbag system according to the present invention.
FIG. 13 is an image diagram of a conventional airbag system.
FIG. 14 is a longitudinal sectional view of an igniter used in a conventional airbag system.
[Explanation of symbols]
10, 11 Bus line

Claims (31)

Used in an airbag system having an electronic control unit connected to a power source and an impact detection sensor, and a plurality of module cases connected to the electronic control unit and containing a plurality of gas generators and airbags. One or more igniters incorporated in the plurality of gas generators,
The airbag system is provided with a bus line composed of a plurality of annular wires that pass through the electronic control unit and supply and transmit current and required information, and a plurality of conductors branch from the bus line at a required portion. Individual gas generators housed in the module case are operatively connected,
One or more igniters incorporated in the gas generator are electric igniters with a heat generating part and an igniting agent in contact with the heat generating part, and the igniter and the bus line are connected by a plurality of conductors. A discharge waveform conversion circuit for converting a signal waveform of a current for igniting ignition ignition stored in the capacitor for each igniter is installed in an integrated circuit in which information for expressing a capacitor and a required function is installed. comprise and, supply of electric current for ignition ignition for one or more igniters are performed via the capacitor in the igniter,
When discharge starts when the waveform of the current supplied from the capacitor is time t = 0, the following equation (I): i (t) = (V ₀ / R) × e ^{−t / CR} (I)
(Where, v ₀ is a capacitor charging voltage (V), R is a circuit resistance (Ω), C is a capacitor capacity (μF), t is a time (μsec), and i is a current (A).)
An igniter for an air bag system having a discharge waveform represented by   2. The igniter for an airbag system according to claim 1, wherein the bus line is composed of two annular wires. The igniter for an airbag system according to claim 1 or 2 , wherein a discharge waveform conversion circuit for converting a signal waveform of a current for igniting ignition stored in a capacitor for each igniter exists in the integrated circuit. Used in an airbag system having an electronic control unit connected to a power source and an impact detection sensor, and a plurality of module cases connected to the electronic control unit and containing a plurality of gas generators and airbags. One or more igniters incorporated in the plurality of gas generators,
The airbag system is provided with a bus line composed of a plurality of annular wires that pass through the electronic control unit and supply and transmit current and required information, and a plurality of conductors branch from the bus line at a required portion. Individual gas generators housed in the module case are operatively connected,
One or more igniters incorporated in the gas generator are electric igniters equipped with a heat generating part and an igniting agent in contact with the heat generating part, and the igniter and the bus line are connected by a plurality of conductors. ,
For each igniter, an integrated circuit in which information for expressing a heat generating part and required functions is recorded is provided on one side of the substrate, a capacitor is provided on the other side, and the substrate is suspended. In addition, a discharge waveform conversion circuit for converting the signal waveform of the current for ignition agent ignition accumulated in the capacitor for each igniter is installed on the same substrate,
An igniter for an air bag system, wherein at least a capacitor and an integrated circuit in the substrate are not in contact with an igniting agent, and a current for igniting agent ignition is supplied to the igniter via a capacitor in the igniter. Used in an airbag system having an electronic control unit connected to a power source and an impact detection sensor, and a plurality of module cases connected to the electronic control unit and containing a plurality of gas generators and airbags. One or more igniters incorporated in the plurality of gas generators,
The airbag system is provided with a bus line composed of a plurality of annular wires that pass through the electronic control unit and supply and transmit current and required information, and a plurality of conductors branch from the bus line at a required portion. Individual gas generators housed in the module case are operatively connected,
One or more igniters incorporated in the gas generator are electric igniters equipped with a heat generating part and an igniting agent in contact with the heat generating part, and the igniter and the bus line are connected by a plurality of conductors. ,
Each igniter has a capacitor installed on the same substrate and an integrated circuit in which information for expressing the required function is recorded, and the substrate is vertically suspended, and further stored in the capacitor for each igniter A discharge waveform conversion circuit that converts the signal waveform of the ignited ignition current is installed on the same substrate,
Further, the substrate and the igniting agent are partitioned vertically by a header for supporting a conductive member that supplies and transmits current between the substrate and the heat generating portion, and the substrate is provided below the header, and the heat generating portion. Is provided above the header,
An igniter for an air bag system, in which an igniter ignition current is supplied to one or more igniters via a capacitor in the igniter. 6. The igniter for an air bag system according to claim 4 , wherein a discharge waveform conversion circuit for converting a signal waveform of a current for igniting ignition stored in a capacitor for each igniter exists in the integrated circuit. The igniter for an airbag system according to any one of claims 4 to 6 , wherein a connection portion between the integrated circuit and the capacitor and the bus line is made of a conductor pattern formed on the substrate by etching. The igniter for an airbag system according to any one of claims 4 to 7 , further comprising a conductive pattern in which a connection portion between the integrated circuit and the heat generating portion and the heat generating portion are formed on the substrate by etching. 9. The igniter for an airbag system according to claim 8 , wherein each of the conductor patterns forming a connection portion between the integrated circuit and the heat generating portion, the capacitor, and the bus line has two paths. 8. The igniter for an air bag system according to claim 7 , wherein each of the conductor patterns forming the connection portion between the integrated circuit and the capacitor and the bus line has two paths. A board is inserted through a header that forms an ignition powder holding space together with a cup member that holds the ignition powder, a capacitor and an integrated circuit are located below the header, and a heat generating part projects upward from the header. The igniter for an airbag system according to any one of claims 4 to 6, 8, and 9 , which is in contact with the air bag. The igniter for an airbag system according to any one of claims 4 to 6, 8, and 9 , wherein a portion excluding the heat generating portion of the substrate is sealed with an insulating material, and the heat generating portion is in contact with the igniting agent. 13. The igniter for an airbag system according to claim 12 , wherein a substrate is provided above a header for supporting a pin serving as an interposed member for supplying and transmitting current and necessary information to and from the integrated circuit and the capacitor. The igniter for an air bag system according to any one of claims 1 to 13 , wherein a function of detecting an abnormality of a heat generating portion of the igniter in the gas generator is recorded in an integrated circuit installed for each igniter. . 15. The igniter for an airbag system according to claim 14, wherein the detected abnormality of the heat generating part of the igniter is disconnection, poor contact between the heat generating part and the ignition agent, or abnormality of the resistance value of the heat generating part. 16. The igniter for an air bag system according to claim 14 , wherein the contact failure between the heat generating portion of the igniter and the ignition agent detects a change in resistance value due to a temperature change of the heat generating portion by a voltage change. The igniter for an air bag system according to any one of claims 1 to 16 , wherein an identification function for each of a plurality of gas generators is recorded in an integrated circuit installed for each igniter.   The igniter for an airbag system according to claim 17, wherein information for developing an identification function for each of the plurality of gas generators is recorded after the gas generator is assembled. The igniter for an air bag system according to claim 17 or 18 , wherein information for expressing an identification function for each of the plurality of gas generators is recorded after the gas generator is incorporated in a module case or attached to a vehicle. The igniter for an airbag system according to any one of claims 1 to 19 , wherein a function for detecting a malfunction of a capacitor is recorded in an integrated circuit installed for each igniter. 21. The igniter for an airbag system according to claim 20 , wherein the information for developing a function for detecting a malfunction of the capacitor is information for measuring a pulse response or a dielectric loss tangent. The igniter for an airbag system according to any one of claims 1 to 21 , wherein a circuit that prevents the igniter from malfunctioning due to noise generated outside the igniter is provided in the igniter. The igniter for an airbag system according to any one of claims 1 to 22 , wherein two or more igniters are provided for each of a plurality of gas generators, Discharge waveform conversion that converts the signal waveform of the current for igniter ignition accumulated in the capacitor for each igniter provided as necessary, and an integrated circuit in which information for expressing the required functions is provided. An igniter for an air bag system that shares a circuit. The igniter for an airbag system according to any one of claims 1 to 22 , wherein two or more igniters are provided for each of a plurality of gas generators, and each igniter includes a capacitor and a required one. For an airbag system having an integrated circuit in which information for expressing a function is recorded, and further having two pins for supplying and transmitting current and necessary information from a bus line to two or more igniters Igniter. Further, in order to charge the capacitor, a circuit having a function of rectifying the current out of the current for charging the capacitor from the bus line and the required information and flowing it to the capacitor as the capacitor charging current is provided in the integrated circuit. 24. The air bag system igniter according to any one of 24 . 26. The igniter for an air bag system according to claim 25 , further comprising a function of amplifying at least one of the rectified capacitor charging voltage and the voltage applied to the bus line in the integrated circuit. An operation control method of an air bag system using the claim 1 to 26 air bag system for an igniter according supply time of the current to the heating portion from the capacitor, a current value corresponding to 5% of the maximum current value A method for controlling the operation of an airbag system, wherein the time is from a point in time to a point in time when the current value is reduced to a current value corresponding to 5% of the maximum current value, and the time is controlled within 500 μsec. When discharge starts when the waveform of the current supplied from the capacitor to the heat generating portion is time t = 0, the following formula (I):
i (t) = (V ₀ / R) × e ^{−t / CR} (I)
(Where, v ₀ is a capacitor charging voltage (V), R is a circuit resistance (Ω), C is a capacitor capacity (μF), t is a time (μsec), and i is a current (A).)
The operation control method for an airbag system according to claim 27 , wherein the discharge waveform is expressed by: The time during which a stable current supply is maintained after reaching the desired current value is defined as t (μsec), and the time from the start of waveform rising until the supply of current for generating heat to the heating unit is stopped when the T (μsec), t and T is (t / T) is 0 ≦ t / T <0.2, or 0.5 <t / T <of claim 27 or 28, wherein satisfies the 1 An operation control method of an airbag system.   27. A method for controlling the operation of an airbag system using the igniter for an airbag system according to claim 1 to 26, wherein a current to the heat generating portion is supplied as an ignition pulse, and the width of the ignition pulse is 20 to 500 μsec. Control method of an air bag system for supplying current to a battery. 31. The operation control method for an airbag system according to claim 30 , wherein a width of the ignition pulse is 40 to 100 [mu] sec.

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