JPH0710972Y2 - Air bag system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an airbag system having a memory for storing abnormality of collision detection means and an airbag operation control section.

[Conventional technology]

As a conventional airbag system, for example, there is one shown in FIG. In FIG. 6, 1 is an on-vehicle battery, 2 is an ignition switch connected to the on-vehicle battery 1, 3 is a controller, 4 is a DC power source for expanding an air bag (not shown), and the on-vehicle battery 1 is connected to the ignition switch 2 via an ignition switch 2. Then, the battery voltage supplied to the controller 3 is boosted by the DC / DC converter 5 for boosting high voltage, and the large-capacity backup capacitor 7 for airbag deployment is charged via the resistor 6.

In this case, the backflow prevention diodes 8a to 8c prevent the backflow, and the diode 9 prevents the current from rushing into the backup capacitor 7 to prevent the backup capacitor 7 from deteriorating. 10 is a diagnostic circuit including a CPU, 11 is a diagnostic circuit power supply unit, which is supplied with battery voltage from the on-vehicle battery 1 and supplies predetermined power to the diagnostic circuit 10 and the non-volatile memory 12 when the ignition switch 2 is turned on. Further, when the ignition switch 2 is off, backup power is supplied to the RAM in the diagnostic circuit 10. Reference numeral 12 is a non-volatile memory such as an EEPROM for exchanging data with the diagnostic circuit 10.

13a to 13e are diodes, and 14 to 19 are collision detecting means provided in each part of the vehicle body, which are configured by arranging acceleration switches 14a to 19a and resistors 14b to 19b in parallel which close the input and output at predetermined accelerations. There is.

Reference numeral 20 denotes a squeeze provided as an operation control unit provided in the steering unit and the like, and serves as an electrode for igniting explosive for deploying an airbag (not shown) provided in the steering unit.

Reference numeral 21 is a spiral cable formed of a flexible cord that is wound around the steering shaft to electrically connect the squeeze 20 and the controller 3 fixedly provided on the vehicle body side.

Further, 3a to 3n are output terminals of the controller, and the output terminal 3a includes the collision detection means 14-output terminal 3b-diode 13a-output terminal 3e-spiral cable 21-squeeze 20.
-It is connected to the line L1 via the output terminal 3f.

The collision detection means 15 is connected between the output terminals 3c and 3d, and the line L
1 to output terminal 3g, line L1 to output terminal 3i, line L1
Diodes 13b to 13e are connected between the output terminal 3k and the output terminal 3k, and between the line L1 and the output terminal 3m.

Output terminals 3g and 3h, output terminals 3i and 3j, output terminals 3k and 3l
Between the output terminals 3m and 3n, collision detection means 16 to 19 respectively.
Are connected.

The output terminals 3h, 3j, 3l, 3n are connected to the line L2. Line L2 is grounded.

Next, the operation will be described. Ignition switch 2
Is closed, the voltage from the vehicle-mounted battery 1 is supplied to the diagnostic circuit power supply unit 11 as well as to the DC / DC converter 5, boosted by the DC / DC converter 5, and determined by the resistor 6 and the capacitor 7. The capacitor 7 is charged with a time constant through the diode 8c, and the charging voltage of the capacitor 7 is always higher than the voltage of the battery 1.

The diagnostic circuit 10 detects the voltage generated in each of the resistors 14b to 19b,
Data such as charging voltage of backup capacitor 7 (DA
TA) and one of the normally open acceleration switches 14a to 19a is in the state of a short circuit, and the voltage generated between the terminals of the resistors 14b to 19b becomes different from the normal value. Judges that it is a failure and stores it in the non-volatile memory 12, and at the same time, the notification unit 23
To drive.

Further, the non-volatile memory 12 stores which acceleration switch is turned on when any of the acceleration switches 14a to 19a is turned on due to a collision or the like.

In the above configuration, when the vehicle collides and negative acceleration more than a predetermined value is generated, and any one of the acceleration switches 14a to 15a and any one of the acceleration switches 16a to 19a are turned on, the electric charge charged in the capacitor 7 is, for example, a broken line. , The squeeze 20 generates heat, gunpowder is ignited, the airbag is deployed, and the occupant is protected.

[Problems to be solved by the device]

However, in such a conventional airbag system, since the nonvolatile memory 12 such as the EEPROM is used to store the failure of the acceleration switches 14a to 19a,
There was a problem that the number of rewrites was limited.

This invention was made in view of such a conventional problem, and by storing the failure of the acceleration switch or the like in the nonvolatile memory and the volatile memory separately for each elapsed time, The purpose is to solve the above problems.

[Means for Solving the Problems]

The airbag system according to the present invention comprises a volatile memory and a non-volatile memory as a memory for storing a failure detected by a diagnostic circuit, and stores the failure time and the failure content in each of these memories. It was made to let.

[Action]

The volatile memory and the non-volatile memory according to the present invention independently store the failure of the operation control unit or the collision detection means, and the failure time in the memory map of the volatile memory indicates the failure time in units of 1 second. Accumulated and stored, and the failure time in the memory map of the nonvolatile memory is accumulated and stored in the memory address of the failure time in units of one hour, thereby suppressing the number of times of writing to the nonvolatile memory.

[Example of device]

The invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of the present invention. First, the configuration will be described. 24 is a volatile memory such as a RAM provided as a memory in the diagnostic circuit 10, and the same components as those shown in FIG. 6 are denoted by the same reference numerals. , And the overlapping description will be omitted. In FIG. 1, reference numeral 11 'denotes a diagnostic circuit power supply unit, which is connected to the battery 1 via a power supply line and is configured to be supplied with backup power. Also, a non-volatile memory (which stores the history until the vehicle is discarded) 12 and a volatile memory (which stores the history until the failure is repaired and is reset after the repair) 24 as the above memory The map is as shown in FIG. 2, and the writing and reading of the data relating to the faults are executed by the microprocessor in the diagnostic circuit 10 according to the procedure of the flowchart of FIG.

Next, the read / write procedure for each of these memory maps will be described with reference to the flowchart of FIG.

Now, in the memory map of FIG. 2, a _{1 to} a ₅ , b _{1 to} b ₅
Is the memory address of the failure content, and a ₆ and b ₆ are the memory addresses of the failure time. First, in the diagnostic circuit 10, the collision detection means 14
~ 19 or failure detection of the squeeze 20 as the operation control unit (step ST1), it is determined whether the failure content is stored in the volatile memory 24 (step ST2),
If not, the failure contents are stored in addresses a ₁ and b ₁ of the memory maps of the volatile memory 24 and the non-volatile memory 12 as shown in FIG. 4 (a) (step ST3). Next, the time when the above-mentioned failure occurs is determined by the addresses a ₁ and b _{1 in the} memory map.
Of the failure contents are stored in at least one of them in 1 second increments and stored at address a ₆ in the memory map of the volatile memory 24 as shown in FIG. 4 (a) ( Step ST4). Next, it is checked whether or not the failure time in the volatile memory 24 has passed one hour (step ST
5) If it does not elapse, re-execute the processing of step ST4 and subsequent steps, and if it elapses, integrate the failure time in units of one hour, and as shown in FIG. It is stored in the memory map at the address b ₆ of the memory 12 (step ST
6). Thereafter, immediately, resets the accumulated time of the volatile memory 24 (step ST7), Figure 4 (c) are shown as stores the failure time of one second increments to address a ₆ of a memory map of the volatile memory 24 Then, the process of the above procedure is repeated.

If there is a history of malfunctions in the past, for example, a non-volatile memory
If the fault is already stored in the address b ₁ of the 12 memory map, a new fault is stored from the address b ₂ .

Next, when one failure has already occurred and this is stored in the addresses a ₁ and b ₁ of the non-volatile memory 12 and the volatile memory 24 as shown in FIG. When a new failure occurs, first, this failure is stored in the memory map address a ₂ of the volatile memory 24 as shown in FIG. 5 (b). Fig. 5 (c)
Address b ₆ of the memory map of the nonvolatile memory 12 as shown in
Is stored in and the integrated time of address a ₆ is reset. further,
As shown in FIG. 5 (d), the elapsed failure time is stored in the address a ₆ in units of 1 second.

[Effect of device]

As described above, according to the present invention, a volatile memory and a non-volatile memory are used as the memory for storing the failure detected by the diagnostic circuit, and the power source of this system is Even if it is destroyed and there are multiple failure data, the failure data before the collision is surely stored in the non-volatile memory, so even if the airbag is not deployed, it may cause trouble between the manufacturer and the user. Even so, it is possible to obtain the effect that the cause can be surely known by examining the stored data and that the performance of the product can be improved based on the data when there is a defect. Further, there is an effect that the number of times of writing in the nonvolatile memory can be reduced.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an airbag system according to an embodiment of the present invention, FIG. 2 is a memory map diagram showing each structure of a volatile memory and a non-volatile memory, and FIG. 3 is a storage of a failure in a memory map. A flow chart showing the procedure, FIGS. 4 and 5 are explanatory views showing an order of rewriting a first occurring fault and a fault subsequently occurring separately into two types of memory maps, and FIG. 6 is a conventional airbag system. It is a circuit diagram showing. 1 ... In-vehicle battery, 2 ... Ignition switch,
10 …… Diagnostic circuit, 12 …… Non-volatile memory (memory), 14
〜19 …… Collision detection means, 20 …… Actuation control section (squeeze), 23 …… Notification section, 24 …… Volatile memory (memory).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Nakano 2-1910 Nisshin-cho, Omiya-shi, Saitama Kanto Seiki Co., Ltd. (72) Shinichiro Tsurushima 2-1910 Nisshin-cho, Omiya-shi, Saitama Kanto Seiki Within the corporation (56) References JP-A 61-156340 (JP, A) JP 62-16376 (JP, Y2)

Claims (1)

[Scope of utility model registration request] 1. At least one collision detection means (14) to (19) connected between terminals of an on-vehicle battery (1) via an ignition switch (2) and a detection output from the collision detection means. An operation control section (20) for inflating an airbag based on the air bag, and a diagnostic circuit (10) for checking a failure of at least one of the operation control section and the collision detection means,
In an airbag system including a notification unit (23) for reporting a failure detected by the diagnostic circuit and a memory for storing the failure detected by the diagnostic circuit, the memory includes a volatile memory (24) and a nonvolatile memory. Sex memory (12)
In addition, the diagnostic circuit performs a failure check every unit time, and when a failure is detected, the failure content and failure time are sequentially stored in the volatile memory, and only when a new failure is detected. The failure content is stored in a non-volatile memory, and when the failure time accumulated in the volatile memory exceeds a predetermined time longer than the unit time, the failure time is transferred to the non-volatile memory and stored therein. Air bag system.