JPH0930365A - Package mounted electronic type air bag device and method for fitting the air bag device to vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide both the package mounted electronic type air bag device which positively can prevent erroneous expansion, and the method for fitting the device to a vehicle. SOLUTION: The device is integrally equipped with an air bag unit 8, an acceleration sensor 9, a collision judgement circuit 10 which detects collision so as to output its operation signal 18 to a drive circuit 5 for expanding an air bag, and with a capacitor 4 which is connected to an on-vehicle battery 32 through an ignition switch 2 so as to allow electric energy to be accumulated therein. The collision judgement circuit 10 is provided with two modes, that is, a permission mode permitting an operation signal to be outputted, and a non-permission mode permitting the operation signal not to be outputted, at least, the non permission mode can be switched over to the permission mode, when the device is in the non-permission mode, the device is provided with a warning signal generating means providing a warning signal, and switch-over can be made by turning an ignition switch 2 ON/OFF for plural times within a specified period of time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device which is a vehicle occupant protection device, and more particularly, when an integrated module including an airbag, a gas generator and an electronic sensor system is mounted on a steering wheel. It is related to the technology for preventing accidental explosion.

[0002]

2. Description of the Related Art In general, an air bag module (air bag device) is a so-called collectively mounted module in which a sensor system is integrally incorporated together with an air bag and a gas generating agent, and a sensor system is separated from a vehicle body. There is a so-called separately mounted module that is installed at the location. Among them, the collectively mounted electronic airbag module includes an airbag unit attached to a gas generator that ejects gas for inflating an airbag, an acceleration sensor that detects a change in acceleration when a vehicle body collides, and the acceleration sensor. A collision determination circuit for determining the presence or absence of a vehicle collision based on a signal from the vehicle, an actuation circuit for issuing an ignition signal to a squib (electric detonator) which is an ignition device of the gas generator, and a viewpoint of preventing malfunction by an electronic circuit only. A collision sensor etc. that closes the contact point by a collision arranged from the above is integrated and modularized so that it can be mounted on the steering wheel at once. In this module, electric energy normally supplied from an on-vehicle battery via an ignition switch is stored in a backup capacitor arranged in the operating circuit, and when a vehicle collision occurs, a collision occurs based on a signal from an acceleration sensor. The judgment circuit detects the collision and outputs an operation signal to the operation circuit. Thus, the operating circuit supplies the electric energy stored in the backup capacitor to the squib to ignite the squib, and the ignition causes the gas generator to operate to deploy the airbag.

[0003] This one-time mounting type electronic air bag device is assembled in the central portion of the steering wheel of an automobile, and also has a built-in collision sensor (and also a safing sensor) which closes the contact point by impact. Therefore, in order to prevent accidental explosion at the time of assembly, a safety mechanism is usually provided in the above-mentioned operating circuit. For example, JP-A-63-2229
As described in Japanese Patent Publication No. 54-54, a safety switch having a normally closed contact for short-circuiting both ends of a squib of an operating circuit is provided, or a pin is provided on a steering wheel together with the safety switch, and an airbag module is installed. When assembled to the steering wheel, the pin comes into contact with the safety switch to open its contact, and the airbag is allowed to be deployed (active).

[0004]

However, even if the above-mentioned safety mechanism is adopted, it is difficult to completely prevent erroneous explosion during mounting. That is, the airbag module is assembled to the steering wheel in the final process of the automobile assembly line, but at the time of this installation, the operation test of various parts is also performed at the same time, so the ignition switch is turned on in all of the front and rear processes. Each process is carried out in this state. To assemble, first connect the connector such as power supply,
Next, the air bag module is fitted into the mounting part at the center of the steering wheel. Since this mounting part is a narrow space, when it is tightly fitted, an impact may be applied at the last hit. Then, in the completely fitted state, the pin pushes the safety switch to allow the airbag to be inflated, so that the ignition switch is turned on.
Because of the N state, the backup capacitor is in a charged state. As a result, the collision sensor may be closed due to the impact at the time of assembly, the circuit may be closed, and an erroneous explosion may occur in the airbag. In addition, there is no guarantee that no shock will be applied in the assembly process after the safety switch is turned on to enter the permitted state, and the stroke of the safety switch and the pin are extremely difficult to adjust. or,
As long as a mechanical safety mechanism is adopted, it is difficult to avoid such a problem even with a method other than the above.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to reliably prevent erroneous explosion when the airbag device is mounted on a vehicle. It is an object of the present invention to provide a collectively mounted electronic air bag device capable of carrying out the above and a method of assembling this device to a vehicle.

[0006]

In order to solve the above-mentioned problems, a collectively mounted electronic airbag device according to the present invention is
An airbag unit mounted on the gas generator, an acceleration sensor for detecting the acceleration of the vehicle, and a drive circuit for inflating the airbag by detecting a collision based on the acceleration signal from the acceleration sensor and operating the same. What is claimed is: 1. A bulk-mounted electronic airbag device that integrally includes a collision determination circuit that outputs a signal, and a capacitor that is connected to an on-vehicle battery through an ignition switch and that stores electric energy from the battery, wherein the collision. The determination circuit has two modes, a permission mode in which the output of the operation signal is permitted and a non-permission mode in which the operation signal is not permitted, and at least switching from the non-permission mode to the permission mode is possible and the non-permission mode is set. In some cases, a warning signal generating means for warning this is provided, and switching from the non-permission mode to the permission mode is It is obtained by the manner performed by multiple ON / OFF operation of the ignition switch in the constant time.

In the above, when the device is in the non-permission mode, the self-diagnosis process of the device is performed, and when an abnormality is detected in the device, it is possible to disable the switching from the non-permission mode to the permission mode. In this case, a warning signal generating means for warning the abnormality may be provided, and the warning may be a signal different from the warning signal for warning that the non-permission mode is set.

Further, it is also possible to switch from the permission mode to the non-permission mode, and this switching operation cannot be performed by the ON / OFF operation of the ignition switch. Furthermore, the ON / OFF operation pattern of both ignition switches is made different. The operation pattern of the ignition switch for switching from the permission mode to the non-permission mode in this case can be made more complicated than the operation pattern for switching from the non-permission mode to the permission mode.

Further, in assembling the above device to a vehicle, a disabling mode is registered in advance in the collision judging circuit, the device is mounted to the vehicle and a connector is connected, and the collision judging circuit is in the disabling mode. After confirming the situation with a warning signal, the mode switch from the non-permission to the permission is turned on multiple times within a predetermined time.
The method of assembling the collectively mounted electronic air bag device to the vehicle by the ON / OFF operation is also the method of the present invention.

By adopting the means as described above, the collision determination circuit is registered in advance in the disapproval mode at the time of assembling the vehicle including the time when the airbag module is attached to the vehicle, and the ignition is performed after the completion of all the assembling. If the mode is switched to the permission mode by operating the switch, the erroneous explosion can be surely prevented since the operation signal itself is controlled not to be output from the airbag microcomputer at the time of assembling the vehicle. At this time, while the collision determination circuit is in the non-permission mode, warnings such as turning on the warning lamp continue to be issued, so if you forget to switch the mode, it will be shipped from the factory in the non-permission mode and the airbag will not deploy. There is no danger of this happening. Further, since the mode is switched by operating the ignition switch, the mode can be easily switched without requiring a communication interface with the microcomputer.

When an abnormal airbag module is installed in the steering wheel, a warning lamp for warning an abnormal condition is lit even if the ignition switch is switched from the non-permission mode to the permission mode. You can check the abnormality immediately as you continue.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram showing the configuration of a collectively mounted electronic airbag device of the present invention, FIG. 2 is a flow chart diagram showing the operation of a microcomputer, FIG. 3 is a graph diagram showing an example of a mode switching operation by an ignition switch, and FIG. FIG. 4 is a schematic process diagram from the production of the airbag device to the user.

First, the construction of the airbag device will be described with reference to FIG. In FIG. 1, the collectively mounted electronic airbag device is an integrated modularized airbag unit 8 having a gas generator, an ignition control unit 1 and the like. A booster circuit 3 boosts the voltage of the vehicle-mounted battery 32 connected via the ignition switch 2 to a predetermined voltage (usually 28 V). A backup capacitor 4 is connected to the booster circuit 3, stores electric energy supplied from the booster circuit 3, and supplies electric energy to the squib 7 even if the current supply from the vehicle-mounted battery 32 is cut off at the time of a collision. Is possible. Reference numeral 5 denotes a squib drive circuit, which is connected to the backup capacitor 4 and is normally in a cutoff state, but becomes conductive when the operation signal 18 is input to supply the electric energy of the backup capacitor 4 to the squib 7. The air bag unit 8 is composed of an air bag (not shown) that is normally folded and stored, a gas generator for generating a gas to deploy the air bag, and the like. The squib 7 is built in the gas generator. . Squib 7 is squib drive circuit 5
The air bag is inflated by operating the gas generator by igniting by the above-mentioned energization. 6 is a safing sensor, which is inserted between the squib drive circuit 5 and the ground, and the contacts are normally open to prevent accidental explosion.
At the time of a collision, the contacts are closed at an acceleration smaller than that of a collision determination circuit 10 to be described later so that the energization of the squib at the time of the collision is not disturbed. The booster circuit 3, the backup capacitor 4, the squib drive circuit 5, the squib 7, and the safing sensor 6 constitute an operation circuit 50 of the airbag unit 8.

On the other hand, 10 is a microcomputer having a built-in collision judgment circuit, which is connected to the acceleration sensor 9 and the squib drive circuit 5 and receives an acceleration signal 1 input from the acceleration sensor 9.
The presence or absence of a collision and the degree of the collision are judged based on 9 and when it is judged as a serious collision for deploying the airbag, the operation signal 18
Is output to the squib drive circuit 5. Therefore, when a vehicle collision occurs, an operation signal is output from the microcomputer 10, the squib drive circuit 5 is turned on, a current is supplied from the backup capacitor 4 to the squib 7, and the gas generator is operated to deploy the airbag. .

The microcomputer 10 has a squib diagnostic circuit 1
3, communication interface 11, EEPROM (electrically rewritable read-only memory) 12, warning lamp 17
Is connected. The squib diagnostic circuit 13 is further connected to the operating circuit 50 to diagnose the presence / absence of disconnection of the circuit, and the data thereof is stored in the EEPROM 1 via the microcomputer 10.
2 and output to the outside through the communication interface 11, and if an abnormality is detected, a warning lamp 17
Is turned on. The warning lamp 17 is installed in the instrument panel or the steering wheel so as to call the driver's attention.

Further, the microcomputer 10 includes a low voltage detector 31.
The voltage of the vehicle-mounted battery 32 (ignition switch 2) or the backup capacitor 4 selectively connected by the switch 30 is stepped down to 5V by the step-down circuit 16 and supplied as the operating voltage. Further microcomputer 10
The ignition voltage Ei is input to the battery 32 from the battery 32, and the microcomputer 10 monitors the voltage Ei. Further, the ignition voltage Ei is used for mode switching described later. Reference numeral 14 is a watchdog timer and 15 is a reset circuit for preventing the microcomputer 10 from running out of control.

Next, the contents of the program for setting the collision determination circuit built in the microcomputer 10, which is a feature of the present invention, to the non-permission mode or the permission mode will be described with reference to the flowchart of FIG. In this example, the ignition switch 2 of FIG. 1 is operated to turn ON / OFF the ignition voltage Ei so that the mode of the collision determination circuit built in the microcomputer 10 is switched.

In FIG. 2, the ignition key is turned on.
Then, the current mode state recorded in the EEPROM is read (step # 2),
It is judged whether or not it is the "non-permission mode" (step # 3),
If it is not the "non-permission mode", the process proceeds to the normal airbag deployment determination process (step # 13). In the disapproval mode, blinking of the warning lamp indicating the disapproval mode (for example, every 0.2 seconds) is started (step # 4). In the non-permission mode, the self-diagnosis process of the device is then performed (step # 14), and it is determined whether or not there is an abnormality in the device (step # 15). When it is determined that there is an abnormality, a warning lamp indicating the abnormality blinks. (For example, at intervals of 0.5 seconds) or it is displayed constantly (step # 16) to warn the driver or worker of the abnormality. Therefore, in this case
It is not possible to proceed to the routine for shifting to the mode (steps # 6 to 9). Various operations performed with the ignition switch turned on in the vehicle body assembly process are also performed at this step #
Since it will be performed in the state of 4, there is no possibility of accidental explosion of the airbag device. Incidentally, the non-permission mode is stored in advance in the EEPROM of the airbag device that arrives at the vehicle assembly plant.

Next, the mode is switched from "non-permitted" to "permitted" by a switch operation that is not performed by an ignition switch operation for normal operation preparation. That is, after confirming the above-mentioned "non-permission mode" with a warning lamp and further confirming that there is no abnormality in the device, the ignition switch is turned off. Whether or not the ignition switch is turned off is detected (step # 5), and if it is not detected (if the ignition switch is still on), the self-diagnosis routine is repeated again, but the switch is turned off. When detected, the timer is started (step # 6). This timer can be set arbitrarily, but is normally set to about 3 to 5 seconds. It is checked if the set time has elapsed in the OFF state (step # 7), and if it is detected that the ignition switch is turned ON again from the OFF state within the predetermined time (step # 8), this "OFF → ON" It is determined whether or not the operation is a preset number of times (for example, two times) set in advance (step # 9).
Return to When a predetermined number of “OFF → ON” operations are confirmed, the mode is switched from “non-permitted” to “permitted” (step # 10), and this mode is recorded in the EEPROM. Therefore, the ignition switch will be turned on next time.
When it is done, the mode is "permitted mode" from the beginning. When the mode is switched to the permission mode, the blinking of the warning lamp disappears (step # 11), so that the operator can confirm the mode switching. Then, normal ignition determination and self-diagnosis processing are started (step # 12).

By the way, if it takes time to operate the ignition switch, it is possible to turn on / off the predetermined number of times within a predetermined time.
Since it has not been turned off, it is determined in step # 7 that the time has expired, the process returns to step # 5 again, and the ignition switch is turned on / off again. Also, if the ignition switch is left off, the timer in step # 6 starts to operate, but the backup capacitor is discharged, so all circuits automatically stop within a few seconds. become.

The ON / OFF detection of the ignition switch in the above step is performed by the microcomputer 1 as described above.
Since 0 monitors the ignition voltage Ei, it can be judged by this voltage change. Even if the ignition voltage Ei is cut off, the microcomputer 10 can execute the program of each of the above steps by the energy stored in the backup capacitor. Therefore, in the ON / OFF operation performed in a short time, the operations in steps # 6 to 9 are executed without any problem, and the non-permission mode is switched to the permission mode.

[0022]

Next, the mode switching operation will be described in more detail with reference to the embodiment shown in FIG. FIG. 3 (a) shows a switching operation from the non-permission mode to the permission mode. The ON / OFF operation of the ignition switch is repeated twice within 3 seconds (,) and the third time () is permitted. It becomes a mode. On the other hand, when the warning lamp is turned on for the second time (,), it flashes every 0.2 seconds to warn that it is in the non-permission state. When the permission mode is entered by turning on the third time (), the light is continuously turned on for 6 seconds and then turned off. Although this warning lamp is also used as a warning of diagnostic abnormality, in the case of diagnostic abnormality, it blinks in a different pattern from the warning in the disapproval mode, that is, blinks at 0.5 second intervals or is continuously lit. Since the switching from the non-permission mode to the permission mode is performed in the assembly process of the automobile manufacturer, the pattern (code) A is relatively simple.

From the viewpoint of preventing erroneous explosion of the present invention, it is sufficient if it has the above functions, but it is also possible to add the following functions. That is, FIG. 3B shows an operation in the case where the permission mode can also be switched to the non-permission mode. Pattern B shown in the figure, that is, ON for 2 seconds
() → 1 second OFF → 1 second ON () → 1 second OFF → 1
Second ON () → 1 second OFF → 2 seconds ON () → 1 second OF
When a complicated ignition switch operation of F →→ 1 second ON () → 1 second OFF → ON () is performed (-), the 6th ON state () results in a non-permission state, and the warning lamp blinks as described above (for example, 0.3 second cycle). Since it is impossible to manually perform the ON / OFF operation while accurately measuring the ON / OFF time as 1 second or 2 seconds, for example, it has a width of about ± 0.2 seconds. It goes without saying that the ignition switch can be turned on / off while measuring the time sensuously.

Further, since the switching from the permission mode to the non-permission mode is supposed to be carried out at the dealer factory after the automobile is purchased and used by the user, the pattern cannot be caused by the user's operation. Therefore, the pattern B is complicated as shown in the figure. It should be noted that the pattern shown in the figure is an example and needless to say, other patterns may be used, but both patterns may be the same.

Next, a method of operating the above-mentioned airbag device will be described in accordance with steps with reference to FIG. In FIG.
At the airbag device manufacturer, the ignition operation of the airbag device is confirmed, and the acceptance / rejection of shipping is determined (20). The accepted product is stamped with a postmark (21), and the encryption B is directly input using the communication interface 11 of FIG.
Record the disallowed mode in the OM. Next, in an automobile manufacturer's assembly process, after the airbag module has been installed in the steering wheel, the warning lamp blinks (23) when the ignition switch is turned on for an operation test or the like. During this assembling process, since it is in the disapproval mode, no accidental explosion occurs even if there is any impact. Further, since the warning lamp continues to blink, there is no fear of forgetting to switch modes. Next, the ignition switch is operated to input the code A in FIG. 3 to switch the mode from the non-permission mode to the permission mode (24). As a result, the warning lamp is also turned off, and the product is shipped from the factory in this state.
Next, when the air bag device is to be removed with the ignition switch turned on at the dealer's factory for vehicle inspection, etc., the ignition switch is operated and the code B in FIG.
Is input to switch from the permission mode to the non-permission mode (25). When the inspection is over, the operation of switching to the permission mode described above is performed again, and it is handed over to the user.

[0026]

According to the collectively mounted electronic airbag apparatus of the present invention having the above-mentioned structure, the following remarkable effects can be expected. (1) The airbag device of the present invention is provided with two modes, a non-permission mode in which the output of the operation signal for operating the airbag is not permitted and a permission mode in which the output of the activation signal is permitted, and from the non-permission mode to the permission mode. Since it is possible to switch to the, it is possible to install the airbag device on the vehicle in the disallowed mode, and it is possible to reliably prevent accidental explosion even if there is some impact in the assembly process. It will be possible. (2) In the case of the non-permission mode, since the warning signal generating means for warning this is provided, it is possible to prevent forgetting to switch to the permissive mode. (3) As described above, in the case of the electronic air bag device, the microcomputer is provided for judging the collision, and the ordinary device is also provided with the EEPROM for the diagnosis. From the viewpoint of cost reduction, it is possible to ensure accidental explosion prevention only by adding software, without the need for additional software, and without requiring mechanical parts such as safety switches and pins as in the past. , Its effect is great. (4) Since the only operation required for mode switching is the ON / OFF operation of the ignition switch, it is possible to easily perform mode switching without the need for a communication interface with a microcomputer in the automobile assembly process.
The complexity of the assembly process is reduced. (5) Furthermore, if it is possible to switch from the permission mode to the non-permission mode, not only in a fully equipped automobile assembly plant, but also in an insufficiently equipped automobile maintenance plant, at the repair stage of the vehicle in use, Since it is possible to switch from the permission mode to the non-permission mode and perform work such as replacement of the airbag device, the safety of erroneous explosion prevention is further improved not only in the assembly plant but also in the repair plant.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a configuration of a collectively mounted electronic airbag device of the present invention.

FIG. 2 is a flowchart showing the operation of a microcomputer.

FIG. 3 is a graph showing a mode switching operation by an ignition switch.

FIG. 4 is a process drawing of an airbag device.

[Explanation of symbols]

 2 Ignition switch 8 Airbag unit (airbag) 9 Acceleration sensor (sensor) 10 Microcomputer (collision determination circuit) 18 Actuation signal 32 In-vehicle battery 50 Actuation circuit

Claims (8)

[Claims] 1. An airbag unit (8) mounted on a gas generator, an acceleration sensor (9) for detecting acceleration of a vehicle, and an airbag by detecting a collision based on an acceleration signal from the acceleration sensor. Is connected to a vehicle-mounted battery (32) through an ignition switch (2) and a collision determination circuit (10) that outputs an operation signal (18) thereof to a drive circuit (5) for developing the vehicle. In the collectively mounted electronic airbag device integrally provided with a capacitor (4) for storing electric energy, the collision determination circuit (10) is in a permission mode in which the output of the operation signal (18) is permitted and is not permitted. It has two modes, a non-permission mode, and at least it is possible to switch from the non-permission mode to the permissive mode. A warning signal generating means for notifying the user is provided, and switching from the non-permission mode to the permission mode is performed by an ignition switch (2) within a predetermined time.
An electronic air bag device that can be installed all at once by being turned on and off multiple times. 2. When the collision judgment circuit (10) is in the non-permission mode, a self-diagnosis process of the device is performed, and when an abnormality is detected in the device, the switching from the non-permission mode to the permissive mode is disabled. The collectively mounted electronic airbag device according to claim 1. 3. When a device abnormality is detected as a result of the self-diagnosis of the device, the device has a warning signal generating means for warning the abnormality, and the warning signal and the warning signal for warning the non-permission mode. Are different in their modes.
The electronic air bag device for all-in-one installation described in. 4. The all-in-one electronic airbag device according to claim 1, wherein the warning signal is blinking of a warning lamp. 5. The switching from the permission mode to the non-permission mode is not possible, and the switching can be performed by a plurality of ON / OFF operations of the ignition switch within a predetermined time. The bulk-mounted electronic airbag device according to any one of the above. 6. The operation pattern of an ignition switch for switching from the permission mode to the non-permission mode and the operation pattern of the ignition switch from the non-permission mode to the permission mode are different operation patterns. All-in-one electronic air bag device described. 7. The operation pattern of an ignition switch for switching from the permission mode to the non-permission mode is made more complicated than the operation pattern of the ignition switch from the non-permission mode to the permission mode. All-in-one electronic air bag device. 8. An airbag unit (8) mounted on a gas generator, an acceleration sensor (9) for detecting acceleration of a vehicle, and an airbag by detecting a collision based on an acceleration signal from the acceleration sensor. Is connected to a vehicle-mounted battery (32) through an ignition switch (2) and a collision determination circuit (10) that outputs an operation signal (18) thereof to a drive circuit (5) for developing the vehicle. A capacitor (4) for accumulating electric energy is integrally provided, and the collision determination circuit (10) is provided with the operation signal (1
8) has two modes, a permit mode permitting output and a non-permit mode not permitting, and at least switching from the disallow mode to the permit mode is possible. When assembling the collectively mounted electronic air bag device including the warning signal generating means for issuing a warning to the vehicle, the collision determination circuit (10) is attached to the vehicle in a state where the disabling mode is registered in advance, and After connecting the connector with the connector, the collision determination circuit (10)
Is confirmed to be in the non-permission mode by the warning signal generating means, and then the non-permission mode is switched to the permissive mode by a plurality of ON / OFF operations of the ignition switch (2) within a predetermined time. A method of assembling the electronic air bag device, which is a feature of the package, into a vehicle.