JP2006044307A - Air bag deploying device and air bag deploying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air bag deploying device and an air bag deploying method capable of lessening the consumption of a battery by suppressing the discharge amount of electricity accumulated in a capacitor and shortening the working time of a charger circuit when the capacitor is to be charged again. <P>SOLUTION: The air bag deploying device 1 selects a plurality of squibs 2 in the specified sequence and deploys an air bag by supplying the ignition voltage to the squibs 2. A control circuit 22 senses the resistance values of the squibs 2, performs diagnosis whether each squib 2 is in the normal state, and controls the charging voltage of the capacitor C and the deploying time on the basis of the resistance values of the squibs 2 obtained by the squib diagnosis. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an airbag deployment device used to dispose of an airbag device, wherein the airbag deployment (expansion) is performed by a squib direct energization method in which a single or a plurality of squibs are connected and an ignition voltage is supplied to the squib. ) The present invention relates to an airbag deployment device that performs processing and a deployment control method thereof.

  2. Description of the Related Art Conventionally, there has been proposed an airbag device that can activate an inflator without removing the airbag device from the steering wheel when the airbag device is discarded (see Japanese Patent Application Laid-Open No. 8-80801).

JP-A-8-80801

  However, since the above-mentioned Patent Document 1 uses an in-vehicle power source and an ECU (electronic control unit), the inflator can be activated when the in-vehicle power source is deteriorated or the ECU is damaged when the airbag device is discarded. Therefore, the subject that an airbag apparatus cannot be discarded arises.

  The present invention has been conceived in view of the above circumstances, and its purpose is to directly connect a squib without using an on-vehicle power supply or ECU, and supply a voltage for ignition to each squib. An airbag deployment device that can dispose of an airbag device even when the in-vehicle power supply is deteriorated or the ECU is damaged by performing airbag deployment (inflation) processing by a method, and a deployment control method for the airbag deployment device Is to provide.

  In order to achieve the above object, the invention according to claim 1 of the present invention connects one squib and supplies an ignition voltage to the squib for a predetermined deployment time to perform airbag deployment processing. An airbag deployment device for performing a battery power supply, a capacitor for supplying an ignition voltage to the squib, a voltage for boosting the voltage of the battery power supply, and a charging circuit for charging the capacitor with the boosted voltage, Charge voltage detection means for detecting the charge voltage of the capacitor, switch means interposed between the capacitor and the squib, and detecting the resistance value of the squib to diagnose whether the squib is in a normal state Squib diagnostic means to perform, storage means for storing the charging voltage and expansion time of the capacitor according to the resistance value of the squib, and diagnosis of the squib diagnostic means The capacitor charging voltage and the development time corresponding to the resistance value of the squib obtained by the results are read from the storage means, and the capacitor charging is stopped when the read capacitor charging voltage is reached during capacitor charging. And a control means for controlling the charging time of the capacitor and controlling the expansion time by switching the switch means from the conductive state to the cutoff state when the read expansion time is reached from the start of the expansion processing. It is characterized by.

As described above, the airbag deployment device according to the present invention includes a battery power source, and is configured to supply a squib ignition voltage by a capacitor charged by the battery power source. Do not use in-vehicle power supply or ECU. Therefore, even when the in-vehicle power source is deteriorated or the ECU is damaged, the airbag device can be reliably discarded.
In addition, since it is configured to control the charging voltage and deployment time of the capacitor in accordance with the squib resistance value obtained from the diagnosis result of the squib diagnostic means, the amount of electric discharge accumulated in the capacitor is suppressed, and again The operation time of the charging circuit when charging the capacitor can be shortened. Thereby, battery consumption can be reduced.

  According to the second aspect of the present invention, one squib of a specific type among a plurality of types of squibs each having a different resistance value is connected, and an ignition voltage is supplied to the squib for a predetermined deployment time. An airbag deployment device that performs a deployment process of a bag, wherein a battery power source, a capacitor that supplies an ignition voltage to the squib, and a voltage of the battery power source are boosted, and the capacitor is charged by the boosted voltage. Whether the squib is in a normal state by detecting a charging circuit, a charging voltage detecting means for detecting a charging voltage of the capacitor, a switch means interposed between the capacitor and the squib, and a resistance value of the squib Squib diagnostic means for diagnosing whether or not, and charging voltage and expansion of the capacitor according to each resistance value of the plurality of types of squibs having different resistance values The storage means for storing the interval, and the charging voltage and the development time of the capacitor corresponding to the resistance value of the squib obtained from the diagnosis result of the squib diagnostic means are read from the storage means, and when the capacitor is charged, When the charging voltage is reached, the charging of the capacitor is stopped to control the charging voltage of the capacitor, and the switch means is changed from the conductive state to the cut-off state when the read expansion time is reached from the start of the expansion process. And control means for controlling the development time by switching.

  Even with such a configuration, the same effects as those of the first aspect of the invention can be achieved.

  According to a third aspect of the present invention, a plurality of squibs each having at least one different resistance value are connected, the plurality of squibs are sequentially selected, and an ignition voltage is respectively applied to each squib with a predetermined development. An airbag deployment device that performs airbag deployment processing by supplying only for a time, a battery power source, a capacitor that supplies an ignition voltage to the squib, and a voltage of the battery power source that are boosted, and the boosted voltage Charging circuit for charging the capacitor, charging voltage detecting means for detecting a charging voltage of the capacitor, switch means interposed between the capacitor and the plurality of squibs, and resistance values of the plurality of squibs. Squib diagnostic means for detecting whether or not each squib is in a normal state, and resistance values of the plurality of squibs. The storage means for storing the charging voltage and the expansion time of the capacitor corresponding to each, and the charging voltage and the expansion time of the capacitor corresponding to the resistance value of the squib obtained from the diagnosis result of the squib diagnosis means are stored from the storage means. When reading and charging the capacitor, the capacitor charging is stopped when the read capacitor charging voltage is reached, and the capacitor charging voltage is controlled, and when the read expansion time is reached from the start of the expansion process And a control means for controlling the development time by switching the switch means related to the squib during the development process from the conductive state to the cut-off state.

With the above configuration, even in an airbag deployment device that connects a plurality of squibs to perform deployment processing of the airbag, by controlling the charging voltage and deployment time of the capacitor, the amount of electric discharge accumulated in the capacitor is suppressed, and again The operation time of the charging circuit when charging the capacitor can be shortened. Thereby, battery consumption can be reduced.
The term “the resistance value is different by at least one” means that the resistance values of a plurality of squibs are different from each other (for example, if there are 10 squibs, all the resistance values of these 10 squibs are all If the resistance value is divided into a plurality of groups (for example, if there are 10 squibs, two of them are resistance A ohm, 3 are resistance B ohm, 5 are squib) In the case of a resistance value C ohm) and the like.

  According to a fourth aspect of the present invention, there is provided the airbag deployment device according to the third aspect, wherein the control means is configured to control execution / stop of a boost function in the charging circuit, and charging the capacitor. The voltage control is performed by stopping the boosting function of the charging circuit by the control means.

  Further, the invention according to claim 5 is the airbag deployment device according to claim 3 or 4, wherein the squib diagnostic means detects a constant current element for supplying a constant current to the squib and a voltage between terminals of the squib. And a conversion means for converting a detection voltage detected by the detection line into a resistance value.

  With the above configuration, the squib resistance value can be easily detected with a simple configuration.

  The invention according to claim 6 is the airbag deployment device according to any one of claims 3 to 5, wherein the plurality of squibs include an airbag squib and a pretensioner squib. The squib and the pretensioner squib have different resistance values.

  With the above-described configuration, the airbag deployment process can be performed on the two types of squibs, that is, the airbag system and the pretensioner system, with the optimum charging voltage and deployment time of each capacitor.

  The invention according to claim 7 includes a battery power supply, a booster circuit that boosts the power supply voltage of the battery, and a capacitor that is charged by the boosted voltage from the booster circuit, and connects one squib, A deployment control method for an airbag deployment device that supplies an ignition voltage from the capacitor to a squib for a predetermined deployment time to perform deployment processing of the airbag, and detects the resistance value of the squib and the squib is normal A squib diagnostic step for diagnosing whether or not the squib is in a state, and a squib resistance value obtained by the squib diagnosing step from storage means for storing in advance a capacitor charging voltage and a development time corresponding to the squib resistance value A readout step of reading out the charging voltage and expansion time of the capacitor corresponding to the capacitor, and the capacitor obtained by the readout step. Controls the charging process of the capacitor so that the charging voltage of the sub, performs expansion processing deployment time obtained by said reading step, characterized by comprising a charging processing and developing process control step.

  With the above structure, the amount of electricity discharged in the capacitor can be suppressed, the operating time of the charging circuit when the capacitor is charged again can be shortened, and the battery consumption can be reduced.

  The invention described in claim 8 includes a battery power source, a booster circuit that boosts the power supply voltage of the battery, and a capacitor that is charged by the boosted voltage from the booster circuit, and a plurality of types of squibs having different resistance values. Is a deployment control method for an airbag deployment device, in which one squib of a specific type is connected, and an ignition voltage is supplied from the capacitor to the squib for a predetermined deployment time to perform deployment processing of the airbag. A squib diagnosis step for detecting whether or not the squib is in a normal state by detecting a resistance value of the squib, and a capacitor charging voltage corresponding to each resistance value of the plurality of types of squibs having different resistance values And storage means for storing the development time in advance, charging of the capacitor corresponding to the resistance value of the squib obtained by the squib diagnosis step. A reading step for reading out the voltage and the expansion time, and a charging process for controlling the charging process of the capacitor so that the charging voltage of the capacitor obtained in the reading step is obtained, and performing the expansion process in the expansion time obtained in the reading step. And a processing / development processing control step.

  Also with the above configuration, it is possible to reduce the amount of electricity stored in the capacitor, shorten the operation time of the charging circuit when the capacitor is charged again, and reduce battery consumption.

  The invention according to claim 9 includes a battery power supply, a booster circuit that boosts the power supply voltage of the battery, and a capacitor that is charged by the boosted voltage from the booster circuit, and each has at least one different resistance value. An airbag deployment device that connects a plurality of squibs, sequentially selects the plurality of squibs, supplies an ignition voltage from the capacitor to each squib for a predetermined deployment time, and performs airbag deployment processing. A squib diagnostic step of detecting whether or not the squib is in a normal state by detecting a resistance value of the squib, and a capacitor according to each resistance value of the plurality of squibs. Corresponding to the resistance value of the squib obtained by the squib diagnosis step from the storage means for storing the charging voltage and the development time in advance. A reading step for reading the charging voltage and expansion time of the capacitor, and controlling the charging process of the capacitor so that the charging voltage of the capacitor obtained by the reading step is obtained, and the expansion processing is performed with the expansion time obtained by the reading step. And a charging process / deployment process control step.

  With the above configuration, in the airbag deployment device that deploys airbags by connecting multiple squibs, the discharge amount of electricity stored in the capacitor is suppressed, and the operation time of the charging circuit is reduced when the capacitor is charged again. Battery consumption can be reduced.

  The invention according to claim 10 is the deployment control method for an airbag deployment device according to claim 9, wherein the squib diagnosis step applies a constant current to the squib and detects the voltage between the terminals of the squib at that time. The detection voltage is converted into a resistance value.

  The invention according to claim 11 is the deployment control method for an airbag deployment device according to claim 9 or 10, wherein the plurality of squibs include an airbag squib and a pretensioner squib. The squib and the pretensioner squib have different resistance values.

According to the present invention, since the in-vehicle power source and the ECU are not used as in the conventional example, the airbag device can be reliably discarded even when the in-vehicle power source is deteriorated or the ECU is damaged.
In addition, since it is configured to control the charging voltage and deployment time of the capacitor in accordance with the squib resistance value obtained from the diagnosis result of the squib diagnostic means, the amount of electric discharge accumulated in the capacitor is suppressed, and again The operation time of the charging circuit when charging the capacitor can be shortened. Thereby, battery consumption can be reduced.

  Hereinafter, the present invention will be described in detail based on embodiments. Note that the present invention is not limited to the following embodiments.

    FIG. 1 is a plan view showing an external configuration of an airbag deployment device according to an embodiment, and FIG. 2 is a side view thereof. The airbag deployment device 1 uses a squib direct energization method as a deployment method. For this reason, a plurality of squibs 2 a to 2 h (generally indicated by reference numeral 2) are provided on the upper portion of the airbag deployment device 1 in FIG. 1. ) Are directly connected to each other. Further, on the surface of the airbag deployment device 1, there are provided a mode select switch operation piece 4 and a deployment operation button 6 for executing a squib deployment process.

  The mode select switch operation piece 4 is used for selectively switching between a power OFF mode, a power ON mode, and an idle (diagnosis) mode. The state in which the mode select switch operation piece 4 is inserted is the power OFF mode, the state in which the mode select switch operation piece 4 is slightly rotated to the right is the power ON mode, and the mode select switch operation piece 4 is further rotated to the right. The state is the idle (diagnostic) mode.

  The unfolding operation button 6 is pushed when the diagnosis / deployment mode is set, so that unfolding processing is executed.

  In addition, the airbag deployment device 1 according to the present embodiment can connect eight squibs 2a to 2h, and can perform batch deployment processing. Therefore, the normal / abnormality of each squib 2a to 2h is operated. For example, a plurality of display lamps 7a to 7h (generally referred to as reference numeral 7) realized by LEDs are provided for visually informing a person, of which the display lamp 7a is a squib for a driver's airbag. The indicator lamp 7b is for a passenger seat airbag squib, the indicator lamp 7c is for a driver seat pretensioner squib, the indicator lamp 7d is for a passenger seat pretensioner squib, and the indicator lamp 7e is This is for the driver side airbag squib, and the indicator lamp 7f is for the passenger side airbag squib, and the indicator lamp 7g 7h is a spare of the squib. The plurality of display lamps 7 are lit in green when normal, for example, are lit in red when short, and are turned off when open.

  Further, a power display lamp 7i, a preparation display lamp 7j, and an operation display lamp 7k are provided in association with the mode select switch operating piece 4 and the unfolding operation button 6. The power indicator lamp 7i lights green when the battery voltage is normal (usable), lights orange when the battery voltage is low (usable), and red when the battery voltage is bad (unusable) Lights on.

  The ready display lamp 7j blinks during the squib diagnosis and lights up when the diagnosis is completed. Further, even after the operation (deployment) button 6 is pressed, the lighting is continued until the deployment is started, and is turned off when the energization (deployment) is started for the squib.

  The in-operation display lamp 7k blinks from the start of the operation (development) process (1 second after the operation button 6 is pressed), lights up upon completion (including halfway stop), and turns on once (on). This state is maintained until the reset mode is restored.

  As described above, the airbag deployment device 1 is configured to visually notify the operator of the squib diagnostic result, the deployment processing state, and the like by using a plurality of display lamps.

  FIG. 3 is a block diagram showing an electrical configuration of the airbag deployment device. The airbag deployment device 1 includes a battery power source 20 (in this embodiment, four batteries having an open circuit voltage of 1.4 V and a nominal voltage of 1.2 V are mounted), and a capacitor C that supplies an ignition voltage to the squib. And a booster circuit 21 that boosts the voltage of the battery power supply (12 V in the present embodiment), a control circuit 22, and a display drive circuit 23 that drives and displays the display lamps 7a to 7k.

  In the figure, SW1 is a power ON mode switch for the mode select switch operating piece 4, SW2 is an idle (diagnostic) mode switch for the mode select switch operating piece 4, and SW3 is turned ON when the operation button 6 is pressed. This is a switch for deployment mode. In the figure, D1 and D2 are backflow prevention diodes, and D3 is a constant current diode. The constant current diode D3 functions to allow a constant current to flow through the squib during squib diagnosis.

  In the figure, Q1 is a switching transistor, and the ON / OFF is controlled by the control circuit 22. When the switching transistor Q1 is ON, charging of the capacitor C is started by the voltage from the booster circuit 21. The charging voltage of the capacitor C is detected by the control circuit 22 via the line M1. Further, the booster circuit 21 is in a boostable driving state when a booster permission signal is given from the control circuit 22 via the line M2. Note that the voltage of the battery power supply 20 is detected by the control circuit 22 via the line M3.

  Also, in the figure, Q2a to Q2h are switching transistors, and ON / OFF is controlled by the control circuit 22. When the switching transistors Q2a to Q2h (generically referred to by reference numeral Q2) are ON, the ignition voltage is supplied from the capacitor C to the corresponding squib and the expansion is executed.

  Also, in the figure, Q3a to Q3h are switching transistors, and ON / OFF is controlled by the control circuit 22. When these switching transistors Q3a to Q3h (generally indicated by reference numeral Q3) are ON, the constant current from the constant current diode D3 flows to the corresponding squib, and the voltage between the terminals of the squib at that time is the line M4. The signal is read by the control circuit 22 via the amplifier circuit 25, and the measured voltage is converted into a resistance value to diagnose normality / abnormality of the squib.

  Further, as shown in FIG. 4, the control circuit 22 determines the CPU 30, the system program, the high reference voltage value Vh and the low reference voltage value Vl, which will be described later, the capacitor charging voltage and the development time according to the squib resistance value, and the like. It comprises a ROM 31, a RAM 32, a plurality of timers T, analog / digital conversion circuits 33 and 34, an input port 35, and an output port 36. Note that the ROM 31 may use, for example, an EPROM, the RAM 32 may use, for example, a DRAM, and other types of memory (eg, EEPROM, SRAM, flash memory, etc.) may be used arbitrarily.

  Note that the booster circuit 21, the switching transistor Q1, and the like constitute a charging circuit.

  Next, the operation of the airbag deployment device 1 configured as described above will be described. The airbag deployment device 1 basically performs a battery voltage confirmation process shown in FIG. 5 and a squib diagnosis / deployment process shown in FIG.

(Battery voltage confirmation process)
FIG. 5 is a flowchart showing a battery voltage confirmation process. The battery voltage confirmation process will be described with reference to FIG. When the switch SW1 is turned on by operating the mode select switch operation piece 4 to turn on the power (step S1), all the display lamps 7 are turned on for confirmation of the display lamps 7 (step S2). The lighting time is 2 seconds in this embodiment as the time required for confirmation. This lighting time is time-controlled by a timer T. Time management in other battery voltage confirmation processing and time management in squib diagnosis / deployment processing described later are also performed by the timer T.

  Next, it is determined whether 0.5 second has elapsed after the switch SW1 is turned on (step S3). When 0.5 second has elapsed, the process proceeds to step S4, and charging of the capacitor C is started. . In the initial state of power-on, the booster circuit 21 is in a boost prohibition state, the switching transistor Q1 is in an OFF state, and each switching transistor Q2 is in an OFF state. When 0.5 seconds elapses, the control circuit 22 gives a boost permission signal to the booster circuit 21 to place the booster circuit 21 in a booster permission state and turn on the switching transistor Q1. Thereby, the boosted voltage is applied to the capacitor C, and charging of the capacitor C is started.

  Next, it is determined in step 5 whether or not 0.1 second has elapsed. If it has elapsed, the process proceeds to step S6, where the initial voltage of the battery power source 20 is confirmed. Specifically, when the detection voltage value V is given to the control circuit 22 (more precisely, the CPU 30 in the control circuit 22) via the line M1, the CPU 30 in the control circuit 22 sets the high reference set in advance from the ROM 31. The voltage value Vh and the low reference voltage value Vl are read, and the detected voltage value V is compared with the high reference voltage value Vh and the low reference voltage value Vl.

  Here, in the present embodiment, the high reference voltage value Vh is set to 4.8V (the nominal voltage of the battery power supply 20 (= 1.2 × 4V)), and the low reference voltage value Vl is set to 4.6V. ing.

  Then, when the comparison result is the detection voltage value V> the high reference voltage value Vh, it is determined to be normal (operable state), and the power display lamp 7i is lit in green. When the high reference voltage value Vh> the detected voltage value V> the low reference voltage value Vl, it is determined that the voltage is insufficient (however, the operation is possible), and the power display lamp 7i is lit in orange. When the low reference voltage value Vl> the detected voltage value V, it is determined that the voltage is insufficient (inoperable state), and the power display lamp 7i is lit in red. Thereby, the operator can visually check the capacity state of the battery power supply 20.

  Since the booster circuit 21 is operated to charge the capacitor C when the power is turned on in this way, the battery voltage during actual use can be confirmed. Therefore, for example, in the case of a configuration in which the voltage of the battery power supply 20 is detected only during the driving operation, even if the remaining capacity of the battery power supply 20 is small, the determination is made based only on the voltage of the battery power supply 20, so that In other words, when actual deployment processing (charging the capacitor) is performed, the voltage drops, charging becomes insufficient, and the deployment cannot be performed. However, in the case of the present embodiment, the voltage of the battery power supply 20 at the time of actual use is detected by operating the booster circuit 21 and charging the capacitor C before the start of operation, and the subsequent development process This avoids a situation where the battery is insufficiently charged and cannot be deployed.

  In step S7, when it is determined that the low reference voltage value Vl> the detected voltage value V and the voltage is insufficient (inoperable state), the inoperable state is set (step S8). Specifically, processing is performed so as not to give a boost permission signal to the booster circuit 21. Thus, in the state as it is, even if the operation button 6 is pressed, the unfolding process is not executed.

  As will be described later, in the battery voltage confirmation process during operation, even when it is determined that the low reference voltage value Vl> the detected voltage value V and the voltage is insufficient (operational disabled state), the voltage is The operation is permitted when the voltage recovers to the low reference voltage value Vl or higher, but the initial voltage confirmation process at power-on remains inoperable even if the voltage subsequently recovers to the low reference voltage value Vl or higher. It is. Thereby, it is possible to prevent a malfunction from occurring in the voltage confirmation of the battery power supply 20 during actual use.

  Next, when 2 seconds have elapsed, the process proceeds from step S9 to step S10. During the squib unfolding process, the normal voltage confirmation process is performed every 0.1 seconds in steps S10 and S11. Specifically, similarly to the above-described initial voltage check process, the detected voltage value V is compared with the high reference voltage value Vh and the low reference voltage value Vl, and the detected voltage value V> the high reference voltage value Vh. Is determined to be normal (operable state), the power display lamp 7i is lit in green. When the high reference voltage value Vh> the detected voltage value V> the low reference voltage value Vl, the voltage is insufficient (however, When the low reference voltage value Vl> the detected voltage value V, it is determined that the voltage is insufficient (inoperable state) and the power display lamp 7i is turned on. Lights red. As described above, even when it is determined that the low reference voltage value Vl> the detected voltage value V and the voltage is insufficient (inoperable state), the voltage subsequently recovers to the low reference voltage value Vl or more. In such a case, the operation is permitted, and the expansion process can be continued.

  Then, when the switch SW1 is turned off, the voltage confirmation process of the battery power supply 20 ends (step S12).

(Squib diagnosis / deployment process)
FIG. 6 is a flowchart showing the squib diagnosis / deployment process. With reference to FIG. 6, the squib diagnosis / deployment processing power will be described.

  First, when the switch SW2 is turned on (step R1), the control circuit 22 outputs a boost permission signal to the booster circuit 21, whereby the booster circuit 21 is in a boostable operation state (step R2).

  Next, in the closed loop of Step R3 → Step R4 → Step R3, diagnostic processing is sequentially executed for all the squibs 2. More specifically, first, the squib 2a is diagnosed. At the time of diagnosis, the control circuit 22 sets the booster circuit 21 in a boost enable state, turns off the switching transistor Q1, and turns off all the switching transistors Q2. Further, the switching transistor Q3a is turned on, and the other switching transistors Q3b to Q3h are turned off. As a result, the output from the booster circuit 21 is made constant through the constant current diode D3, and this constant current is supplied to the squib 2a. Thus, if the terminal voltage of the squib 2a is measured via the line M4, the resistance value of the squib 2a can be converted from the measured voltage, and as a result, the resistance value of the squib 2a can be known.

  In the present embodiment, the measurement voltage of the squib 2 a is amplified by the amplifier circuit 25 and supplied to the control circuit 22 in order to improve the measurement accuracy. The control circuit 22 calculates the resistance value of the squib 2a from the measured voltage, and performs normal / abnormal diagnosis. Then, the squib diagnostic process as described above is performed for all the squibs 2a to 2h, and when the diagnosis for all the squibs 2a to 2h is completed, the process proceeds to step R5 and the diagnosis result is displayed. As described above, the diagnosis result display is performed by turning on the green light when the squib display lamps 7a to 7h are normal, turning on the red light when they are short, and turning off the light when they are open.

  Next, the expansion process is performed for the squib 2 determined to be normal based on the diagnosis result. Specifically, the unfolding process is started by pressing the operation button 6 (step R6). Next, in step R7, the boost permission signal is given to the booster circuit 21, and the booster circuit 21 enters the boost permission state. Next, in step R8, charging of the capacitor C is started. That is, the switching transistor Q1 is turned on and all the switching transistors Q2 are turned off. Thereby, charging of the capacitor C is started.

  Then, in step R9, it is determined whether or not 0.5 second has elapsed from the start of charging. If not, the process proceeds to step R10, where the charging voltage of the capacitor C is confirmed. Specifically, the control circuit 22 detects the charging voltage of the capacitor C via the line M1. Then, by the closed loop processing of Step R9 → Step R10 → Step R11 → Step R9, the capacitor C is charged within 0.5 seconds from the start of charging until it reaches a predetermined voltage.

  Here, it should be noted that the charging voltage of the capacitor C and a later-described development time are made variable in accordance with the resistance value of the squib 2 obtained by the squib diagnostic process. More specifically, the squib 2 used in the present embodiment includes an airbag system (whether for a driver seat, a passenger seat, or a driver seat side) and a pretensioner system (for a driver seat or a passenger seat). The air bag squib 2 (resistance value is 2 ohms) and the pretensioner squib 2 (resistance value is 2.15 ohms) have different resistance values. Therefore, by changing the charging voltage of the capacitor C and the later-described development time according to the resistance value of the squib, the driving time of the booster circuit 21 can be shortened, and the battery consumption can be reduced.

  Specifically, the charging voltage and the deployment time shown in Table 1 below are set according to the air bag squib and the pretensioner squib. As described above, the charging voltage and the expansion time are stored in a table in the ROM 31, and the charging voltage and the expansion time are read out to the CPU 30 during the charging of the capacitor and the expansion processing described later, Predetermined processing is performed.

  In other words, in the case of a 2 ohm squib, it is necessary to keep a current of at least 1.75 A flowing for 2 mSec for deployment, and for this purpose, the charging voltage of the capacitor C is 4.6 V. In the calculation of the charging voltage, the capacitance of the capacitor C is calculated as 3300 farads. Similarly, in the case of a 2.15 ohm squib, it is necessary to keep a current of at least 2.0 A flowing for 1 mSec for deployment, and for this purpose, the charging voltage of the capacitor C is 5. 0V is required.

  Therefore, in the confirmation process of the charging voltage of the capacitor C in step R10, the charging voltage of the capacitor C is detected. In the case of an air bag squib, when the voltage reaches 4.6V, the boost permission signal to the booster circuit 21 is stopped, The drive of the booster circuit 21 is stopped. In the case of a pretensioner squib, when the voltage reaches 5.0 V, the booster permission signal to the booster circuit 21 is stopped and the drive of the booster circuit 21 is stopped.

  Next, when 0.5 seconds elapses, the process proceeds from step R9 to step R12 to determine whether or not the voltage of the capacitor C is a predetermined voltage. If the voltage of the capacitor C is not the predetermined voltage, the squib is Since it is not normal, the expansion process is not performed (step R13).

  In step R12, when the voltage of the capacitor C is a predetermined electric voltage, the process proceeds to step R14 to perform a developing process. That is, the expansion process is performed only for normal squibs. The unfolding process is performed by turning off the switching transistor Q1 and turning on the switching transistor Q3 corresponding to the squib to which a current should flow. As described above, the deployment time is variable according to the resistance value of the squib.

  Next, in step R15, it is determined whether or not all the squibs have been processed. If not, the process returns to step R9. The unfolding process is performed by turning off the switching transistor Q1 and turning on the switching transistor Q3 corresponding to the squib to be unfolded among a plurality of squibs.

  In this way, the unfolding process is sequentially performed on the normal squib by a series of processes of steps R9 to R16.

  For reference, the deployment is achieved even if the capacitor C is charged to the same voltage (for example, about 10 V) and deployed with the same deployment time (2 mSec) regardless of the squib resistance value. It is possible to do. However, in such a processing method, the booster circuit is driven more than necessary, and the battery electricity is wasted. On the other hand, as in the present embodiment, by changing the charging voltage and the development time of the capacitor C according to the resistance value of the squib, the amount of electric discharge accumulated in the capacitor is suppressed, and the The driving time of the booster circuit when accumulating the voltage can be shortened, and the battery consumption can be reduced.

(Other matters)
(1) In the above-described embodiment, the airbag deployment device that connects a plurality of squibs and collectively deploys the plurality of squibs has been described. However, the present invention is not limited to this, and one squib is used. The present invention can also be applied to an airbag deployment device that performs a deployment process by connecting.

(2) In the above embodiment, the squib resistance value is two types, but may be three or more types. In addition, although the capacitor charging voltage and expansion time are switched between two values, in the case of a squib having three or more different resistance values, the capacitor charging voltage and expansion time can be varied according to the resistance value. You may make it.

  The present invention can be suitably implemented in an airbag deployment device that deploys one squib or an airbag deployment device that deploys a plurality of squibs at once.

It is a top view which shows the external appearance structure of the airbag deployment apparatus which concerns on embodiment. It is a side view of the airbag deployment apparatus concerning an embodiment. It is a block diagram which shows the electric constitution of the airbag deployment apparatus which concerns on embodiment. It is a block diagram which shows the specific structure of a control circuit. It is a flowchart which shows the battery voltage confirmation process in the airbag deployment apparatus which concerns on embodiment. It is a flowchart which shows the squib diagnosis and the expansion | deployment process in the airbag expansion | deployment apparatus which concerns on embodiment.

Explanation of symbols

1: Airbag deployment device 2a-2h: Squib
4: Mode select switch operation piece 7a-7k: Lamp for display
20: Battery power
21: Booster circuit
22: Control circuit
C: Capacitor SW1 to SW3: Switch

Claims (11)

An airbag deployment device that connects one squib, supplies an ignition voltage to the squib for a predetermined deployment time, and deploys the airbag.
Battery power,
A capacitor for supplying an ignition voltage to the squib;
A charging circuit that boosts the voltage of the battery power supply and charges the capacitor with the boosted voltage;
Charging voltage detecting means for detecting a charging voltage of the capacitor;
Switch means interposed between the capacitor and the squib;
Squib diagnostic means for detecting whether or not the squib is in a normal state by detecting a resistance value of the squib;
Storage means for storing the charging voltage and expansion time of the capacitor according to the resistance value of the squib;
The capacitor charging voltage and the development time corresponding to the resistance value of the squib obtained from the diagnosis result of the squib diagnosing means are read from the storage means, and the capacitor is charged when the capacitor charging voltage read at the time of capacitor charging is reached. Control to control the charging voltage of the capacitor by stopping the charging of the capacitor and switching the switching means from the conductive state to the cut-off state when the read expansion time is reached from the start of the expansion processing. Means,
An airbag deployment device comprising: An airbag deployment device that connects one squib of a specific type among a plurality of types of squibs each having a different resistance value, and supplies the ignition voltage to the squib for a predetermined deployment time to perform airbag deployment processing. Because
Battery power,
A capacitor for supplying an ignition voltage to the squib;
A charging circuit that boosts the voltage of the battery power supply and charges the capacitor with the boosted voltage;
Charging voltage detecting means for detecting a charging voltage of the capacitor;
Switch means interposed between the capacitor and the squib;
Squib diagnostic means for detecting whether or not the squib is in a normal state by detecting a resistance value of the squib;
Storage means for storing the charging voltage and expansion time of the capacitor according to each resistance value of a plurality of types of squibs having different resistance values;
The capacitor charging voltage and the development time corresponding to the resistance value of the squib obtained from the diagnosis result of the squib diagnosing means are read from the storage means, and the capacitor is charged when the capacitor charging voltage read at the time of capacitor charging is reached. Control to control the charging voltage of the capacitor by stopping the charging of the capacitor and switching the switching means from the conductive state to the cut-off state when the read expansion time is reached from the start of the expansion processing. Means,
An airbag deployment device comprising: A plurality of squibs each having a different resistance value are connected, the plurality of squibs are sequentially selected, and an ignition voltage is supplied to each squib for a predetermined deployment time. An airbag deployment device for performing
Battery power,
A capacitor for supplying an ignition voltage to the squib;
A charging circuit that boosts the voltage of the battery power supply and charges the capacitor with the boosted voltage;
Charging voltage detecting means for detecting a charging voltage of the capacitor;
Switch means respectively interposed between the capacitor and the plurality of squibs;
Squib diagnosis means for detecting the resistance values of the plurality of squibs and diagnosing whether or not the squib is in a normal state;
Storage means for storing the charging voltage and expansion time of the capacitor corresponding to the resistance values of the plurality of squibs,
The capacitor charging voltage and the development time corresponding to the resistance value of the squib obtained from the diagnosis result of the squib diagnosing means are read from the storage means, and the capacitor is charged when the capacitor charging voltage read at the time of capacitor charging is reached. The charging of the capacitor is stopped and the charging voltage of the capacitor is controlled, and the switch means related to the squib during the expansion process is switched from the conductive state to the cut-off state when the read expansion time is reached from the start of the expansion process. Control means for controlling the deployment time,
An airbag deployment device comprising:   The control unit is configured to control execution / stop of a boosting function in the charging circuit, and the charging voltage control of the capacitor is performed by stopping the boosting function of the charging circuit by the control unit. The airbag deployment apparatus of description. The squib diagnostic means includes
A constant current element for supplying a constant current to the squib;
A detection line for detecting the voltage between the terminals of the squib,
Conversion means for converting the detection voltage detected by the detection line into a resistance value;
The airbag deployment apparatus of Claim 3 or 4 provided with these.   The airbag development according to any one of claims 3 to 5, wherein the plurality of squibs include an airbag squib and a pretensioner squib, and the airbag squib and the pretensioner squib have different resistance values. apparatus. A battery power supply, a booster circuit that boosts the power supply voltage of the battery, and a capacitor that is charged by the boosted voltage from the booster circuit, and one squib is connected to the squib with an ignition voltage from the capacitor A deployment control method for an airbag deployment device that supplies a predetermined deployment time to perform airbag deployment processing,
A squib diagnostic step for detecting a resistance value of the squib and diagnosing whether or not the squib is in a normal state; and
A reading step of reading out the charging voltage and expansion time of the capacitor corresponding to the resistance value of the squib obtained from the squib diagnosis step from storage means for storing in advance the charging voltage and expansion time of the capacitor according to the resistance value of the squib; ,
A charging process / expansion process control step for controlling the charging process of the capacitor so as to be the charging voltage of the capacitor obtained by the reading step, and performing the expansion process with the expansion time obtained by the reading step;
A deployment control method for an airbag deployment device, comprising: A battery power source, a booster circuit that boosts the power supply voltage of the battery, and a capacitor that is charged by the boosted voltage from the booster circuit, and each one of a plurality of types of squibs having different resistance values A deployment control method for an airbag deployment device that performs an airbag deployment process by supplying an ignition voltage from the capacitor for a predetermined deployment time to the squib,
A squib diagnostic step for detecting a resistance value of the squib and diagnosing whether or not the squib is in a normal state; and
The charging voltage of the capacitor corresponding to the resistance value of the squib obtained by the squib diagnosis step from the storage means for storing in advance the charging voltage and the development time of the capacitor corresponding to each resistance value of the plurality of types of squibs having different resistance values And a reading step for reading out the development time;
A charging process / expansion process control step for controlling the charging process of the capacitor so as to be the charging voltage of the capacitor obtained by the reading step, and performing the expansion process with the expansion time obtained by the reading step;
A deployment control method for an airbag deployment device, comprising: A battery power supply, a booster circuit that boosts the power supply voltage of the battery, and a capacitor that is charged by the boosted voltage from the booster circuit, and connects a plurality of squibs each having at least one different resistance value. A deployment control method for an airbag deployment device that sequentially selects a squib, supplies an ignition voltage from the capacitor for a predetermined deployment time to each squib, and deploys the airbag.
A squib diagnostic step for detecting each of the resistance values of the squib and diagnosing whether or not the squib is in a normal state;
The charging voltage and expansion time of the capacitor corresponding to the resistance value of the squib obtained by the squib diagnosis step are read out from storage means for storing in advance the charging voltage and expansion time of the capacitor corresponding to each resistance value of the plurality of squibs. A reading step;
A charging process / expansion process control step for controlling the charging process of the capacitor so as to be the charging voltage of the capacitor obtained by the reading step, and performing the expansion process with the expansion time obtained by the reading step;
A deployment control method for an airbag deployment device, comprising:   The deployment of the airbag deployment device according to claim 9, wherein the squib diagnosis step is performed by passing a constant current through the squib, detecting a voltage between terminals of the squib at that time, and converting the detected voltage into a resistance value. Control method.   The deployment control of the airbag deployment device according to claim 9 or 10, wherein the plurality of squibs include an airbag squib and a pretensioner squib, and the airbag squib and the pretensioner squib have different resistance values. Method.