JP3448633B2 - Operation control device for inflator for airbag device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air bag device operation control device for detecting a collision of a vehicle and operating the air bag device, and more particularly to deploying one air bag by a plurality of inflators. The present invention relates to a deployment control device for a new airbag device, which is capable of appropriately determining the operating mode of the inflator and the necessity of operating the airbag device according to the degree of collision.

[0002]

2. Description of the Related Art Conventionally, an air bag device generally used is a system in which one inflator deploys one air bag. In this method, an acceleration sensor installed inside the vehicle always detects a change in the acceleration of the vehicle, performs an appropriate calculation process such as one-time integration or two-time integration, and compares the acceleration signal with a predetermined threshold value. If the threshold value is exceeded, an activation signal is issued to the ignition circuit of the inflator to activate the inflator and inflate the airbag.

According to the safety standard, this system is 50 k
It is designed to exert its maximum ability in the case of a head-on collision at a speed of m / h. Therefore, regardless of the severity of the collision and the position or posture of the occupant, if the threshold value is exceeded, the airbag will have a constant level. It is designed to develop with characteristics. Therefore, in the case of a collision of medium to low speed, the airbag is deployed with excessive deployment energy to protect the occupant, and when the position of the occupant is close to the airbag or the physique of the occupant is small, The airbag deployed by the occupant could cause injury.

In addition, at the mounting position of the acceleration sensor for determining whether or not the inflator needs to be operated, an integrated type in which the sensor is integrated with the airbag module and mounted on the steering wheel, and an operation in the vehicle interior are performed. There are two types, a separated type arranged on the side of the seat, and in the case of the integrated type, the impact of a collision transmitted through the steering shaft is detected by an acceleration sensor. An acceleration sensor is installed on a mounting bracket arranged in the vehicle body, and the impact of a collision transmitted to the vehicle interior through the vehicle body is sensed by the acceleration sensor. In either case, the rigidity is high, that is, At the time of a collision, the necessity of airbag deployment is judged based on the change in acceleration sensed through the acceleration sensor installed in the passenger compartment, which does not deform significantly. .

Further, in some vehicles in which the impact of the front of the vehicle is difficult to be transmitted to the passenger compartment, an electronic acceleration sensor is installed in the passenger compartment, and a mechanical sensor is arranged in a crash zone such as an engine room in the front of the vehicle body. The system is adopted,
Due to its characteristics, the mechanical sensor can only make on / off judgments, and because it makes a parallel judgment with the collision judgment system using the acceleration sensor in the passenger compartment, a local impact such as hammering is input to the mechanical sensor. If this happens, there is a possibility of malfunction.

In recent years, a so-called "inflatable form" is controlled by installing a plurality of inflators and appropriately controlling the output of the inflator according to the form of collision and the condition of the occupant. A method called a "smart airbag system" has been proposed, but in order to realize this method, it is necessary to make an ignition determination earlier than the conventional ignition determination timing for the calculation of the output control of the inflator. However, there is no proposal for such an early judgment method.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to perform ignition determination at an appropriate timing earlier than in conventional systems. At the same time, there is a possibility of malfunction due to proper judgment even in the case of incorrect usage such as rough road and hammering (hereinafter referred to as "abuse"), which may cause malfunction by judgment only by the vehicle interior acceleration sensor. It is an object of the present invention to provide a novel airbag operation control device in which the air bag is significantly reduced.

[0008]

SUMMARY OF THE INVENTION The present invention has been made based on this point of view, and is characterized in that in addition to a conventional electronic first acceleration sensor installed in a vehicle interior, An electronic second acceleration sensor is also installed in the crash zone at the front of the vehicle body, and a first time integrated value time-integrated based on an acceleration signal from the first acceleration sensor and an acceleration from the second acceleration sensor. A second time integrated value time-integrated based on a signal and an integrated value difference between the first time integrated value and the second time integrated value, or a difference in characteristics between these and the change amount of the integrated value difference in various collision modes. Based on the above, the necessity of activating the inflator is determined,
The operating mode of the inflator is determined based on the magnitude of the time difference between the time until the first time integrated value exceeds the predetermined speed threshold and the time until the second time integrated value exceeds the predetermined speed threshold. It will be. Further, in addition to the magnitude of this time difference, the operating mode of the inflator is determined by a combination with the magnitude of the time until the first time integrated value or the second time integrated value exceeds a predetermined speed threshold value. It is also possible to do so.

There are two types of inflator operation modes: a rapid deployment method in which the inflator is actuated so as to rapidly deploy the airbag, and a slow deployment method in which the inflator is actuated so as to gently deploy the airbag. For the rapid deployment method that activates the inflator simultaneously,
There is a slow expansion method that sequentially operates a plurality of inflators with a time lag, and a rapid expansion method that sequentially operates a plurality of inflators with a minute time difference is performed by increasing the ignition time difference of the plurality of inflators. There is a method of slowly expanding.

Further, there are the following ten methods for judging whether or not the inflator needs to be operated. (A) A method of comparing the first time integral value with a predetermined first speed threshold value of a time function and judging by the magnitude thereof (b) The first time integral value as a function of the second time integral value A method of comparing with a predetermined second speed threshold that is determined and judging by its magnitude (c) Comparing the second time integral value with a predetermined third speed threshold that is determined as a function of the first time integral value (D) A method of comparing the difference in integrated value between the first time integrated value and the second time integrated value with a fourth speed threshold of a predetermined time function, and making a determination based on the size ( e) A method of comparing the change amount of the integrated value difference (time differential value of the difference of the integrated value) with a difference change threshold value of a predetermined time function, and judging by the magnitude thereof (f) (d), (e) ) Conditions are arranged in parallel, and at least one of them Method for judging whether or not to add (g) The conditions (d) and (e) above are arranged in parallel, and the condition (a) is further added to at least one of the above (d) and (e). Satisfies the operating condition and determines whether or not the condition (a) is satisfied. (H) The predetermined fifth difference which is set as the function of the first time integrated value by the time integrated value difference. Method of comparing with speed threshold value and judging by its magnitude (i) Method of arranging conditions (e) and (h) above in parallel and judging by whether at least one of them satisfies the operating condition (j) A method of arranging the conditions (c) and (e) in parallel, and determining based on whether at least one of them satisfies an operating condition.

By adopting the above-mentioned system, malfunctions such as rough road, unnecessary use or deer collision (collision with animals such as deer. The same applies hereinafter) which does not require the operation of the inflator are prevented, and high speed collision (high collision) is achieved. It makes it possible to properly set the ignition timing in a frontal collision at a speed (the same applies hereinafter) and a high-speed oblique collision (a collision from a diagonally forward front at a high speed. The same applies hereinafter).

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 is a block diagram showing a first embodiment of an airbag operation control device of the present invention. In FIG. 1, an acceleration sensor 1 is a first acceleration sensor that is normally installed in a vehicle interior. Acceleration sensor 2
Is a second acceleration sensor installed in the crash zone. Here, the crash zone refers to a space inside the vehicle body in front of the vehicle interior of the vehicle body, which is a portion which is deformed prior to deformation of the vehicle interior at the time of a collision and has a function of reducing deformation of the vehicle interior, Corresponds to the front of the engine room.

The acceleration signals G and G'detected by the acceleration sensors 1 and 2 are passed through the arithmetic circuit 3 to the reset circuit 19 and the trigger circuits 20 and 21 of the two inflators.
Each trigger circuit is configured to ignite each inflator (not shown) to deploy the airbag 22.

Next, the arithmetic circuit 3 will be described.
Acceleration signal G detected by the first acceleration sensor 1 in the vehicle compartment
Is transmitted to a block 4 which is a calculation start determination circuit, and when the acceleration value G exceeds a predetermined acceleration G1, this time t
A predetermined calculation based on the acceleration G is started from 0. Next, a block 5 is an offset processing means, which subtracts a predetermined acceleration G2 from the acceleration value G after the calculation start time t0 to offset the acceleration value G, thereby cutting noise and minute acceleration change. I have to. Then
The acceleration G3 output from the offset means 5 is time-integrated in the integration means 6 to calculate a first time integration value V. On the other hand, the acceleration signal G ′ detected by the second acceleration sensor 2 installed in the crash zone is transmitted to the block 4 ′ which is a calculation start determination circuit, and the acceleration value G ′ detected by the acceleration sensor 2 is predetermined. Acceleration G
When it exceeds 1 ', a predetermined calculation based on the acceleration G'is started from this time t0', and a predetermined acceleration is obtained from the acceleration value G'after the calculation start time t0 'in the block 5'which is the next offset means. The offset acceleration G3 'is calculated by subtracting G2', and then the integrating means 6'integrates the acceleration G3 'over time to calculate the second time integrated value V'.

Here, the first time integration value V obtained by time integration based on the acceleration signal from the first acceleration sensor 1 installed in the vehicle compartment and the acceleration signal from the second acceleration sensor 2 installed in the crash zone are used. The difference from the second time integration value V ′ obtained by time integration based on the above will be described. 12
(A) and (B) are diagrams showing changes with time of V and V ', (A) is a Vt diagram, (B) is a V'-t diagram, and the time axis is shown. t is shown on the same scale. As is clear from both figures, in all collision modes, the second time integrated value V ′ based on the second acceleration sensor 2 in the crash zone is the first time integrated value based on the first acceleration sensor 1 in the vehicle interior. It can be seen that it has reached a large value earlier than V.

Further, in a high-speed head-on collision, which is one particularly serious collision, V ′ rapidly shows a large value, and also in a high-speed oblique collision, which is also one of the serious collisions, V ′ is large. As in the case of a high-speed head-on collision, the value of V increases sharply in the initial stage, while the value of V gradually increases in the initial stage and then increases sharply from the middle. Furthermore, in the case of a medium-speed center pole collision (frontal collision with a columnar body such as an iron column at a medium speed. The same applies hereinafter),
Since the small area centering around the pole collision part is deeply crushed, the value of V is such that only the bumper or the frontmost part of the vehicle body is deformed for a while after the collision, and basically, the low speed that does not require the deployment of the airbag. It shows a value lower than that of a head-on collision, and finally becomes higher than that of a low-speed collision after a considerable amount of time. For this reason, if judged by V, the airbag may not deploy or may deploy at a later delayed time even if deployed, but in the case of V ′, it is higher than the low-speed collision from the beginning. Indicates the value. Further, in the case of a deer collision, only a slight change appears in the case of V, but in the case of V ′, a large value comparable to the maximum value of the low speed collision is shown. This is because even if you collide with a deer, etc., it will be instantly repelled, so a relatively large change in acceleration will appear in the crash zone with deformation, but in the passenger compartment, the shock will be absorbed in the crash zone. , Because there is almost no change. Further, in the case of rough road, V and V ′ show similar waveforms. This is because there is no deformation of the vehicle body itself on rough roads, so there is no difference due to the installation location of the acceleration sensor. As described above, in a medium / high speed collision in which the crash zone in the front part of the vehicle is locally crushed or deformed at the initial stage of the collision, V ′ rises earlier than V and rough road, etc. in which no deformation occurs in the crash zone. In the impact of V, V and V ′ show substantially the same waveform. Also, in a low-speed collision in which the deformation of the crash zone is small, V ′ tends to rise earlier than V.
The difference is decreasing.

From these phenomena, the second time integrated value V'based on the second acceleration sensor 2 installed in the crash zone used in the present invention and the first acceleration sensor 1 installed in the passenger compartment, which has been conventionally used, are used. It can be seen that there is a peculiar difference between the first time integrated value V and the first time integrated value V. Further, it can be seen that the second time integral value V ′ of the crash zone shows a larger rise at an earlier time as the collision becomes more severe. Therefore, in the present invention, based on the difference between the first and second time integral values depending on the collision mode, the degree of the severity of the collision is determined, and at the same time, the appropriate collision determination is performed. There are characteristics.

Next, the method of determining the operating mode of the inflator according to the present invention will be specifically described. The determination method of the operating mode of the inflator according to the present invention determines the severity of the collision based on the magnitude of the time difference until each of the first time integrated value V and the second time integrated value V ′ exceeds a predetermined speed threshold value. Then, the operating mode of the inflator is determined based on this. That is, as shown in FIG. 1, in the comparators 7 and 7 ′, the first time integrated value V and the second time integrated value V ′ are respectively compared with a preset speed threshold value Vs, and each interval is compared. When the integrated value exceeds the threshold value (V ≧ Vs,
Vt ≥ Vs) t and t'are respectively detected, the subtraction means 8 calculates the difference Δt (= t-t ') between the two, and the comparator 12, which is the next inflator operation mode determination device, Compared with a preset time difference threshold Δts, and when the threshold crossing time difference is less than the threshold (Δt <Δts),
Since the time integration value exceeds the speed threshold value at an early stage, it is determined that the collision is a severe one, and a rapid deployment signal (K = 2) is output from the block 14 so as to deploy the airbag rapidly. On the other hand, when the time difference over the threshold value is equal to or more than the threshold value (Δt ≧ Δts), the time integration value is rising relatively slowly, so it is determined that the severity of the collision is low, and the airbag is gently opened. A slow expansion signal (K = 1) is output from the block 13 so as to expand it. When the comparators 7 and 7'determine V <Vs and V '<Vs, the respective calculations are continued.

The slow / rapid expansion signals (K = 1, 2) output from the blocks 13 and 14 are transmitted to the K value judgment circuit 17, and the operation "necessary" is judged by the inflator operation necessity judgment circuit described later. When the signal is transmitted, a trigger command of the inflator is issued to the trigger circuit 20 of the first inflator / the trigger circuit 21 of the second inflator based on the slow / rapid deployment signal to activate the inflator, and the airbag 22 is slowly deployed or It will be deployed rapidly.

Next, this operation mode judgment will be described with reference to FIG. In FIGS. 12A and 12B, in the case of a high-speed head-on collision, the first time integration value V exceeds the speed threshold Vs at time t1, and the second time integration value V ′ is time t1 ′. The velocity threshold Vs is exceeded. Therefore, the threshold crossing time difference Δt1 becomes t1−t1 ′. Similarly, in the case of a high-speed oblique collision, the first time integration value V exceeds the speed threshold value Vs at the time t2, and the second time integration value V ′ is the time t.
At 2 ', the speed threshold Vs is exceeded, and the threshold crossing time difference Δt2 becomes t2-t2'. Similarly, the threshold crossing time difference Δt3 in the case of a middle-speed center pole collision is t3-t.
3 ′, and the threshold crossing time difference Δt4 for a low speed collision is t4−t
4 ', and the rough road threshold crossing time difference Δt5 is t5-
It becomes t5 '. In order to make it easier to understand the time difference between them,
The magnitude of each time difference is shown in FIG. Here, the threshold crossing time difference Δ of each of the high-speed front collision and the high-speed oblique collision, which are serious collisions in which the inflator should be rapidly deployed,
A large difference is clearly recognized between t1 and Δt2 and the over-threshold time difference Δt3 of the middle-speed center pole collision, which is a relatively gentle collision in which the inflator should be deployed slowly. Therefore, to distinguish between the two, Δt1, Δt2 <Δts <
It can be seen that it is sufficient to set the time difference threshold Δts that is Δt3. If such a time difference threshold value Δts is set, in the inflator operation mode determination device 12, rapid deployment is selected in the case of a high-speed front collision or a high-speed oblique collision, and in the case of a medium-speed center pole collision, The slow expansion will be selected.

In the case of a low-speed collision that does not require the deployment of the airbag, the deformation of the crash zone is slight, so that the change in the acceleration value due to the collision is also slightly delayed in the vehicle interior from the change in the crash zone. The threshold crossing time difference Δt4 has a small value. Similarly, in the case of rough road as well, there is no deformation of the crash zone. The overtime difference Δt5 is also a small value. Therefore, both Δt4 and Δt5 also become less than the time difference threshold Δts, and the inflator operation mode determination device 1
In No. 2, the rapid deployment is selected, but in these cases, as will be described later, it is determined that the airbag is not required to be activated and the inflator is not activated. However, in order to surely prevent the malfunction, the time difference threshold Δts is set as the threshold of the time function, whereby it is possible to avoid the misjudgment in the low speed collision or the rough road. That is, the time difference threshold Δ
Let ts be a value represented as a line segment Δts in FIG. 12 (A) in the initial stage, maintain that value for a certain period of time, and a time t4 at which the low-speed collision V, V ′ exceeds the speed threshold Vs.
At t4 ′, the first time integration of the low-speed positive collision in FIG. 12 is performed by a method of using a step function with a low value near zero (0) or a method of using a straight line or a curve that gradually decreases with time. At time t4 when the value V exceeds the speed threshold Vs, the value is not smaller than the threshold crossing time difference Δt4 of the low speed collision, and at time t5 when the first time integrated value V on the rough road exceeds the speed threshold Vs. Then
It is also possible to set the time difference threshold Δts so as to be a value smaller than the rough threshold threshold time difference Δt5.

As another method, as shown in FIG. 12 (A), a time difference threshold Δts1 having the same level as the time difference threshold Δts is set as a first time threshold, which is smaller than this and has a low-speed collision. The second time difference threshold value Δts2 that is larger than the time difference Δt4 is set, and Δts2 <Δt <Δt
Only in the case of s1, do not select the rapid expansion, Δt ≧
It is also possible to select the gentle expansion in the case of Δts1 and to suspend the selection and continue the calculation in the case of Δt <Δts2.

Next, another example of the inflator expansion mode determination method will be described with reference to FIG. In the method of FIG.
The difference from the above method is that the time difference Δt and the time difference threshold Δt are
Along with the comparison with s, the threshold crossing times t and t ′ of the first time integrated value V and the second time integrated value V ′ are also used for determining the operating mode of the inflator. That is, in FIG. 2, the threshold value overshooting time difference Δt and the time difference threshold value Δts are input to the comparator 27, and the first threshold value overshooting time t of the first time integral value V is compared with this in advance. The first time threshold value ts set in the block 23 is input respectively, and as a result of the comparison, the threshold value overtime difference is less than the time difference threshold value (Δt <Δts), and the first threshold value overtime is When it is less than the first time threshold value (t <ts), the rapid expansion (K = 2) is selected, while the time difference is equal to or more than the threshold value (Δt ≧ Δts) or the first threshold crossing time is the first time threshold value. When the time is equal to or longer than the one-hour threshold value (t ≧ ts), the slow expansion (K = 1) is selected. As shown in FIG. 2, instead of the first threshold crossing time t of the first time integration value V, the second threshold crossing time t ′ of the second time integration value V ′ is used, and this is used in the block 27. The second time threshold value ts' preset in block 23 to be input and compared with this
Are input to the block 27 and compared with each other, and Δt <Δt
If s and t '<ts', rapid expansion (K =
If 2) is selected and Δt ≧ Δts or t ′ ≧ ts ′, then it is possible to select the slow expansion (K = 1), comparing t and ts, comparing t ′ and ts ′. Both comparisons may be used, or it is sufficient to use either one.

Next, the operating mode of the inflator will be described. As shown in FIG. 1, in the case where there are two inflators, a first inflator and a second inflator, the airbag is deployed in a mode in which the airbag is gently deployed and rapidly inflated. There are two types, i.e., a method of determining the slow expansion and the rapid expansion by the number of inflator operations, a method of determining the inflator operation timing, and a combination thereof. An example of this combination is as follows. (A) The first method is a method of controlling the slow deployment and the rapid deployment of the airbag by adjusting the ignition timings of the first inflator and the second inflator. A method of gradually expanding the airbag by increasing the ignition timing difference between the inflator and the second inflator, and in rapid deployment, shortening the ignition timing difference between both inflators (including simultaneous ignition) to rapidly ignite the airbag. Is. (B) The second method is a method of controlling the airbag to be slowly deployed and rapidly deployed by the number of actuations of the inflator. In slow deployment, only the first inflator is ignited, and in rapid deployment, the first inflator is ignited. This is a method of igniting both the first and second inflators. In the rapid deployment in this case, by providing a difference (including simultaneous) in the ignition timing of the first inflator and the second inflator, more delicate control is possible. Which of these modes should be selected depends on the characteristics and scale of the inflator to be used, but as a preferable example, when the gas generating capacity of the entire inflator is 10, The ratio of gas generation capacity with 2 inflators is 6: 4 ~
It is preferable to select in the range of 8: 2, and the order of operation is such that the first inflator is operated first.

Incidentally, in FIG. 1, the slowly expanded signal (K =
In 1), there is a line directly input from the block 17 to the first inflator trigger circuit 20, but this shows a case where only the first inflator is activated in the case of slow deployment, and from the block 17 The lines to which both the slow expansion signal (K = 1) and the rapid expansion signal (K = 2) are input to both inflator trigger circuits 20 and 21 are used in cases where the ignition timings of the inflators are shifted and when the inflator is activated. The case where both inflators are operated simultaneously is shown.

Next, the determination as to whether or not the inflator needs to be operated in the present invention will be described. In FIG. 1, the first time integrated value V based on the vehicle interior acceleration sensor 1 is transmitted to a comparator 15 which is an inflator activation necessity determination unit, and here, a first time function of a preset time function is determined in block 16. If the first time integral value is equal to or more than the first speed threshold value (V ≧ Vs1) as compared with the one speed threshold value Vs1, it is determined that the airbag needs to be deployed, and a signal indicating “necessary” for inflator operation is sent to the block 17. If the inflator operating mode signal (K = 1, 2) is transmitted to the block 17 and is transmitted, the inflator is operated according to the operating mode. This operation necessity judgment is a typical judgment method using a conventionally used vehicle interior acceleration sensor, and in the case of a low-speed head-on collision that does not require the operation of the inflator, the first time integrated value V is The first speed threshold Vs1 is set as a threshold of the time function so as not to exceed the first speed threshold Vs1. The present invention can also be adopted as one of the inflator actuation necessity determination methods, and the detailed description thereof will be omitted.

If the first integrated value is less than the first time threshold value (V <Vs1), the comparing means 18 compares V with a preset value of zero (0) or its vicinity. If the value is less than or equal to the set value (for example, zero or less), the system is reset by the system reset circuit 19, and if the value is greater than or equal to the set value (for example, zero or more), the calculation in the arithmetic circuit 3 is continued. .

Next, FIG. 3 shows another embodiment of the present invention, in which the same components as those in FIG. 1 are designated by the same reference numerals. Figure 3
Then, the second time integral value V'is input to the trigger judgment calculation circuit 25 of the inflator, and the second time integral value V'is used to make a primary judgment as to whether or not the inflator should be operated. The second speed threshold value Vs2 of the block 26 is changed based on the above, the changed second speed threshold value Vs2 is input to the comparator 24, and the first calculated based on the first speed sensor 1 described above. The time integrated value V is compared.

That is, since the crash zone is a portion which is first destroyed at the time of a collision, the change of the second time integral value V'based on the second acceleration sensor 2 installed in the crash zone can be seen from FIG. As can be seen, the change ends earlier than the change in the first time integral value V based on the first acceleration sensor 1 normally installed in the vehicle interior. Therefore, if it is determined whether or not the inflator needs to be actuated based on the acceleration signal of the second acceleration sensor 2, it is possible to determine whether or not the inflator needs to be actuated earlier than based on the signal from the first acceleration sensor 1 normally installed in the vehicle interior. Will be done. Therefore, in this example, the second time integrated value V ′ calculated based on the second acceleration sensor 2 is used.
The block 25 is used to make a primary determination as to whether or not the airbag device is required to be operated. As the judgment circuit in this block 25, a system (algorithm) for judging using an acceleration signal from a vehicle interior acceleration sensor that has been proposed and put into practical use can be used, and there is no particular limitation, but the present case The algorithm proposed by the applicant and put into practical use (for example, the algorithm described in Japanese Patent No. 2543839: JP-A-3-253441) is preferable.

Next, in the block 25, when it is determined that the inflator is required to operate, the block 2
Second speed threshold value Vs2 input to the comparator 24 at 6
Is set to a comparatively low value, and when it is determined that the inflator is not required to operate, the second speed threshold value Vs
The value of 2 is set to a high value, and further, it is related to the judgment time in block 25, and when it is judged that the inflator needs to be activated at an early time, the value of Vs2 is set to an extremely low value. A function that changes the second speed threshold Vs2 with the second time integral value V ′, that is, Vs2 = f
It is set as (V ').

Next, the comparator 24 compares the above-mentioned first time integral value V with the second speed threshold value Vs2. If V ≧ Vs2, the slow / rapid expansion index input to the block 17 is entered. The ignition of the first inflator / second inflator is the same as in the case of FIG.
Also, as in the case of FIG. 1, a trigger signal is not issued to each inflator unless both the inflator operation signal from the comparator 24 and the inflator operation mode signal from the blocks 13 and 14 are input. is there.

Next, FIG. 4 shows still another embodiment of the present invention. In the system of FIGS. 1 to 3, the first time integration based on the acceleration signal G from the first acceleration sensor 1 in the passenger compartment is performed. Although it is determined whether or not the inflator should be operated based on the value V, in the method of FIG. 4, the second time integral value V ′ based on the acceleration signal G ′ from the second acceleration sensor 2 installed in the crash zone is set to the inflator. The difference is that it is also used for determining whether or not to operate. That is, in FIG. 4, the second time integrated value V ′ is transmitted to the comparator 28, and the comparator 28 compares it with the third speed threshold Vs3 transmitted from the block 32 to judge whether or not the inflator is required to operate. It is basically different in that it is designed to do. Particularly, this third speed threshold value Vs3 is a function (Vs3 =
f (V)) and the second time integral value is equal to or more than the threshold value (V ′ ≧ Vs3), it is determined that the inflator needs to be activated, and the signal is transmitted to block 17. In block 17, an operation mode signal (K = 1 or K = from the inflator operation mode setting device 13 or 14) is sent.
If 2) is transmitted, a trigger signal is issued to the first and second inflator trigger circuits 20 and 21 in accordance with the respective operating modes. On the other hand, when the second time integration value is less than the fifth threshold value (V ′ <Vs3), the signal is transmitted to the comparator 30 and the second time integration value V ′ is set to a preset zero. If it is smaller than (0) or a value in the vicinity thereof, a signal is sent to the system reset circuit 19 to reset the system, and if V'is a predetermined value or more, the calculation is continued.

The third speed threshold value Vs3 used in this example.
FIG. 16 shows the relationship between (V) and the second time integrated value V ′.
Explained by. FIG. 16 shows the relationship between the second time integration value V ′ based on the acceleration signal from the second acceleration sensor 2 and the time integration value V based on the acceleration signal from the vehicle interior first acceleration sensor 1 in various collision modes. It is a diagram, and the dotted line a at an angle of 45 degrees in the figure means V ′ = V, and V ′ = V is finally obtained in any collision mode. As can be seen from FIGS. 12 (A) and 12 (B), in any collision mode, V ′ has a value higher than V from the time of collision and has a characteristic of approaching V with the passage of time. All lines are above the dotted line a of 45 degrees. The third speed threshold value Vs3 (V) set as a function of V is also set as a function of hyperbolic V between the line a of 45 degrees and the V ′ axis, and is a curve on the V ′ axis side. The minimum V value of c is set to a value that is slightly higher than the level of the deer collision in FIG. 12 (A), and the curved line portion b along the 45-degree line a can identify a low-speed collision. Is set to. As described above, by making the threshold value not the time function but the function of the first time integration value V, stable determination independent of time can be expected.

Next, FIG. 5 shows another example of whether or not the inflator needs to be actuated according to the present invention. In the case of FIGS. 1 to 4, the first time integrated value V or the second time integrated value V ′ is set. In the present example, the subtraction means 9 uses the first time integrated value V
Is calculated by calculating a difference Vd (= V'-V) between the second time integrated value V'and the second time integrated value V ', and the integrated value difference Vd is used for determining whether or not the inflator needs to be operated. That is, the integrated value difference Vd obtained by the subtraction means 9 is previously stored in the block 38 in the comparator 34.
Is compared with the fourth speed threshold value Vs4 set as the threshold value of the time function, and if Vd ≧ Vs4, it is judged that the inflator needs to be operated, and an inflator operation instruction signal is transmitted to the block 17. To do. The block 17 instructs the inflator trigger circuits 20 and 21 to output a trigger signal in accordance with the inflator operation mode signal (K = 1, 2) sent from the block 13 or 14, and the inflator is activated by this trigger signal. Activate
The airbag 22 is deployed.

The integrated value difference is less than the fourth time threshold value (V
In the case of d <Vs4), the comparison means 36 compares Vd with a preset value of zero (0) or in the vicinity thereof, and in the case of a preset value or less (for example, zero or less), the system The reset circuit 19 resets the system, and when the value is equal to or higher than the set value (for example, equal to or higher than zero), the calculation in the calculation circuit 3 is continued.

Next, the relationship between the above Vd and the fourth time threshold value Vs4 will be described with reference to FIG. 13. As shown in FIG. 13, the threshold value Vs4 is higher than the level of the deer collision at the initial stage of the collision. It is set to Th1 so that a serious collision such as a high-speed frontal collision or a high-speed oblique collision is judged at an early stage and an inflator operation command is issued. Further, in the subsequent middle stage of the collision, the low threshold Th in the latter stage of the collision is used.
The gradual decrease threshold value Th2 (threshold value that decreases with time) is decreasing to 3 and the gradual decrease threshold value Th2 is used to determine an intermediate collision such as a middle speed center pole collision and issue an operation command to the inflator. Has become. The low threshold Th3 in the latter stage is for determining whether or not the inflator needs to operate in a low-speed head-on collision, and is set to a value that will not deploy in a head-on collision at a predetermined speed or lower.

The time axis of this figure is also shown on the same scale as the time axis of the Vt diagram of FIG. 12 (A), and as is clear from the comparison of both figures, there is a high-speed front collision or a high-speed oblique collision. In such a serious collision, since it is possible to issue an operation instruction to the inflator at an extremely early stage after the collision, not only the airbag can be deployed promptly, but also the ignition mode of each inflator is judged. It can be seen that since the time margin of is increased, the calculation time for the deployment form control can be afforded, and the airbag deployment form control can be performed by a precise calculation.

By the way, in the case of rough road, FIG.
As shown in (A) and (B), since V and V ′ have almost the same waveform, the difference Vd becomes an extremely small value. From this fact, the malfunction of the airbag due to the rough road can be completely prevented if judged by Vd. Further, even in the case of a slight collision with a small deformation of the vehicle body, the time integrated value difference between both acceleration sensors becomes a small value, so that the malfunction due to this can be reliably prevented.
In this sense, the second acceleration sensor 2 is installed in a portion in the crash zone where deformation is not caused by a low-speed collision such as a low-speed collision, so that the waveforms of V and V ′ are almost the same even in the low-speed collision. Since the difference Vd can also be set to a small value, it is possible to more reliably prevent a malfunction in a low-speed head-on collision.

Next, FIG. 6 shows another embodiment of the present invention. The difference from FIG. 5 is that the integrated value difference Vd is time differentiated (d (Vd) / dt) to calculate a change amount Gd of Vd, and this difference change amount Gd is used for determining whether or not the inflator needs to be operated. That is, the difference change amount Gd is transmitted to the comparator 44, and the comparator 44 compares the difference change amount Gd with the difference change threshold value Gs set as the threshold value of the time function in advance in the block 42 to determine whether or not the airbag needs to be operated. I am trying to do. When the difference change amount is greater than or equal to the difference change threshold (Gd ≧ Gs), it is determined that the inflator operation is “necessary”, and an inflator operation command signal is transmitted to the block 17, and the comparator 12 According to the expansion mode signals (K = 1, 2) of the inflator selected by comparing the threshold crossing time difference Δt and the time difference threshold Δts, the first inflator trigger circuit 20 and the second inflator trigger circuit 20 respectively.
The point of instructing the inflator trigger circuit 21 to output the trigger signal is the same as in the case described above. On the other hand, when the difference change amount is less than the difference change threshold value (Gd <Gs), the comparator 36 compares Vd with a preset value of zero (0) or a value in the vicinity thereof, and sets the set value. In the case of the following (for example, zero or less), the system is reset by the system reset circuit 20, and in the case of the set value or more (for example, zero or more), the calculation in the arithmetic circuit 6 is continued. Same as the case.

Next, the relationship between the Gd and the difference change threshold Gs of the time function will be described with reference to FIG.
FIG. 14 is a diagram showing the relationship between the difference change amount Gd and time t in various collision modes. As shown in FIG.
At the early stage of the collision, the threshold Gs is set to a value Th4 higher than the level of the deer collision, thereby preventing the malfunction of the airbag due to the deer collision, and following the high threshold Th4, to the lower threshold Th6. Threshold value Th of steep slope
In step 5, a serious collision such as a high-speed frontal collision or a high-speed oblique collision is judged at an early stage and an inflator operation command is issued. Further, the middle speed center pole collision can be detected near the low threshold Th6 so that the middle speed center pole collision can be detected at an early time. The low threshold Th6 in the latter stage is
This is for determining whether or not the airbag needs to be deployed in a low-speed head-on collision, and is set to a value such that it will not be deployed in a collision at a predetermined speed or less.

The time axis of FIG. 14 is also Vd-t of FIG.
It is shown on the same scale as the time axis of the diagram, and as is clear from the comparison between the two diagrams, it is important to judge based on Gd, because it is possible to issue an airbag operation instruction at an earlier time. It is possible to quickly determine whether or not the inflator needs to be deployed in the event of a collision, and it becomes possible to allow sufficient time from the determination of whether or not the operation is required to the ignition timing of the inflator. There is an advantage that it is possible to execute. In case of rough road,
Since it is an extremely small value as in the case of Vd described above,
As in the case of Vd, the malfunction of the airbag due to rough road can be completely prevented if judged by Gd.

Next, FIG. 7 is a block diagram showing another embodiment of the present invention, which is the system shown in FIG. 6 in which the necessity of operating the inflator based on Vd is added.
In the comparator 46, the integrated value difference Vd and the variation Gd thereof are input, and each of them is the fourth speed threshold Vs4 of the time function.
And the difference change threshold Gs, and Vd ≧ Vs4, Gd
When either or both of the conditions ≧ Gs are satisfied, it is determined that the inflator needs to be actuated, an inflator actuation instruction signal is transmitted to the block 17, and the comparator 12 which is the inflator actuation mode decision circuit described above is transmitted. When the actuation mode signal (K = 1 or 2) of the inflator determined by the comparison between Δt and the time difference threshold value Δts in (1) is input, the first and second inflator trigger circuits 20, 21
In addition, the trigger instruction signal is output according to the operation mode. The result of the comparison in the comparator 46 is V
When d <Vs4, the comparator 36 compares Vd with a predetermined value, and the result determines whether to reset the system or continue the operation, which is the same as the above-described case.

Here, the point that the inflator needs to be actuated when either of the conditions of Vd ≧ Vs4 and Gd ≧ Gs is satisfied is the same as the case of FIG. 5 or FIG. 6 described above. There is an advantage that various sensitivity settings are possible,
Further, in the system in which the inflator is operated only when both of them are satisfied, double judgment is made, so that there is an effect that reliability is improved.

Next, FIG. 8 is a block diagram showing another embodiment of the present invention. As a judgment as to whether or not to operate the inflator, the judgment based on the integrated value difference Vd in FIG. 7 and the integrated value difference V are used.
In addition to the determination based on the change amount Gd of d, the determination based on the first time integrated value V based on the first acceleration sensor 1 in the vehicle compartment is added. That is, in the comparison means 48, the Vd
And the threshold value Vs4 thereof, and Gd and the threshold value Gs thereof, the first speed threshold value Vs1 preset in the block 16 as the threshold value of the first time integral value V and its time function. And the at least one of Vd ≧ Vs4 and Gd ≧ Gs is satisfied and the condition of V ≧ Vs1 is satisfied, the inflator operation permission signal is output to the block 17. ing. In block 17, the operation mode signal (K
= 1, 2), the trigger signal is issued to the inflator trigger circuit when the operation permission signal is input, as described above. In the case of Vd <Vs4, the description is omitted because it is the same as the above case.

Here, the reason why the determination based on the first time integrated value V is also used is that the value of the first speed threshold Vs1 for the first time integrated value V is set to a relatively low value.
The determination is made substantially by the Vd and Gd, and there is a meaning to prevent malfunction due to these Vd and Gd.

Next, FIG. 9 is a block diagram showing another embodiment of the present invention, showing another example of determining whether or not the inflator needs to be actuated. In the example of FIGS. Although Vd is compared with the threshold value of the time function, this example is characterized in that it is compared with the threshold value of the speed function defined as a function of the first time integral value V. That is, in FIG. 9, the subtraction means 9
The difference Vd between V ′ and V obtained in step S1 is transmitted to the comparator 52, while the block 54 includes the first time integration value Vd.
Is inputted to calculate a fifth speed threshold Vs5 (= f (V)) which is predetermined as a function of the first time integrated value V, and the fifth speed threshold Vs5 is transmitted to the comparator 52.
The comparator 52 compares the two, and if the integrated value difference is equal to or more than the fifth speed threshold value (Vd ≧ Vs5), a trigger permission signal of the inflator is transmitted to the block 17. When the integrated value difference is less than the fifth speed threshold value (Vd <Vs
In 5), Vd is transmitted to the comparison means 36 and compared with a value preset to zero (0) or a value in the vicinity thereof, and when Vd <0 (or a set value near zero), , A signal is sent to the system reset circuit 19 to reset the system, and Vd ≧ 0 (or a set value near zero)
In the case of, the point that the calculation is continued is the same as the case described above.

Next, a comparison between the threshold values Vs5 and Vd of the speed function in this embodiment will be described below. Figure 15
FIG. 5 is a diagram showing the relationship between Vd and V in each collision mode, and the fifth speed threshold value Vs5 of the speed function has a hyperbolic shape, and a curved line portion d rising to the Vd axis side.
Is set so that a deer collision can be discriminated, and the minimum value of V is set to the same level as the above-mentioned first speed threshold Vs1. On the other hand, the gradually decreasing curve e on the V-axis side is set so that a low-speed head-on collision can be discriminated. According to this determination method, a stable determination result can be obtained regardless of time by setting the threshold value as a function of the first time integral value V instead of the time function.

Next, FIG. 10 is a block diagram showing another embodiment of the present invention. As a judgment as to whether or not the inflator needs to be operated, the integrated value difference Vd and the fifth speed threshold Vs of the speed function of FIG. 9 are determined.
In addition to the comparison with FIG. 5, the comparison between the change amount Gd of the integrated value difference and the difference change threshold value Gs is added. That is, in FIG. 10, the comparator 56 has the integrated value difference V
d, the fifth speed threshold value Vs5, and the difference change amount Gd and the difference change threshold value Gs are respectively input, and the respective comparisons are made. Either or both of the conditions of Vd ≧ Vs5 and Gd ≧ Gs are input. When the above condition is satisfied, the trigger permission signal of the inflator is transmitted to the block 17. When Vd <Vs5, Vd at that time
The system reset circuit 19 is operated in accordance with the value of to reset the system or continue the calculation, as in the case described above.

As described above, in addition to the judgment by the fifth speed threshold value Vs5 of the speed function having stability independent of time,
The use of the comparison of the difference change thresholds Gs and Gd of the time function together broadens the range of judgment and enhances reliability, but on the other hand, the inflator operates only when both conditions are satisfied. When the Gd is compared with the difference change threshold Gs as shown in FIG. 14, a serious collision such as a high-speed front collision or a high-speed oblique collision can be judged early. Therefore, in addition to the early judgment of the seriousness of the collision, the certainty based on the speed function threshold is taken into consideration, and the collision judgment with higher reliability becomes possible.

Next, FIG. 11 shows still another example of determining whether or not the actuation of the inflator is required, and compares the integrated value difference Vd shown in FIG. 10 with the fifth speed threshold Vs5 of the speed function. Instead of the second time integration value V ′, the third speed threshold value Vs3 is set as a function of the first time integration value V.
(= F (V)) is used. That is, the first time integration value V that has been time-integrated by the time integration means 6 is stored in the block 32.
The third speed threshold value Vs3 that is preset as a function of the first time integral value V is calculated and transmitted to the comparator 58. On the other hand, to the comparator 58, the second time integral value V ′ is transmitted from the integrator 6 ′, the difference change amount Gd is transmitted from the block 10, and the difference change threshold Gs is transmitted from the block 42. Respectively, where the second time integral value V ′ is compared with the sixth threshold value Vs3 of the speed function, and the difference change amount Gd and the threshold value Gs of the time function.
And Gd ≧ Gs and V ′ ≧ Vs3 2
When either one or both of the two conditions are satisfied, the inflator operation permission signal is output to the block 17. From this meaning, V'and Vs3
Although it is possible to judge whether or not the inflator needs to be operated only by comparing with, it is described in this example that two types of comparison are performed, that is, comparison between Gd and Gs and comparison between V ′ and Vs3. ing.

As a result of the comparison by the comparator 58, V '<Vs
In the case of 3, the value of V ′ is transmitted to the comparator 30, and V ′
Is compared with a value preset to zero (0) or a value in the vicinity thereof, and when V ′ <0 (or a set value near zero), a signal is sent to the system reset circuit 19 and the system When reset and V '≧ 0 (or a set value near zero), the calculation is continued. That is, FIGS.
At 0, the value of Vd at that time was used to determine whether to reset the system or continue the calculation. In this example, however, the value of V'is used. For this judgment, V
It is arbitrary whether d is used, V ′ is used, or V is used as shown in FIGS. 1 to 3, and one which is easy in system design may be selected. From this point of view, it is also possible to determine whether to reset the system or continue the calculation based on the value of Gd at that time.

In the case of FIG. 11 as well, as in the case of FIG. 10, the threshold value Vs of the speed function having stability that does not depend on time.
In addition to the judgment by 3, the comparison of the time function difference change thresholds Gs and Gd is also used, so that there is an effect that the judgment area is expanded and the judgment ability is enhanced. If the operation permission signal is issued to the inflator only when both conditions are satisfied, a serious collision such as a high-speed head-on collision or a high-speed oblique collision can be judged early and the seriousness of the collision can be judged. In addition to early judgment, the certainty of the speed function threshold is added,
A more reliable collision determination is possible and an effect can be expected.

As described above, according to the present invention, the second acceleration sensor is installed in the crash zone in addition to the conventional first acceleration sensor installed in the vehicle compartment, and based on the difference in acceleration value between the two sensors in each collision mode. It is judged whether or not the inflator should be actuated based on the difference between the integrated value and the difference between the two integrated values or the amount of change in the integrated value difference, and time integration based on the acceleration signal signals from both sensors. The greatest feature is that the operating mode of the inflator is determined by the time difference until the value reaches a predetermined level, and as a concrete method there are various methods as shown in FIGS. 1 to 11. Of course, the present invention is not limited to the schemes shown in these drawings, and it goes without saying that various modified examples exist in accordance with the spirit of the present invention.

For example, the first speed threshold value Vs1 and the fourth speed threshold value Vs4 shown as the threshold value of the time function include a constant value threshold value as a special case of the time function, and further described as the threshold value of the time function. The difference change threshold Gs also includes a threshold having a constant value. Also, in FIG. 13 and FIG.
Thresholds Vs4 and Gs of the time function shown as three straight lines
It is also possible to make a curve of the time function.
It is also possible to replace the velocity thresholds Vs5 and Vs6 shown as the function curves of the first time integrated value V in 5 and 16 with a combination of straight lines of the function of V.

Further, the inflator operation mode judging method shown in FIGS. 3 to 11 shows only the method of comparing the threshold overtime difference Δt with the time difference threshold Δts, which is shown in FIG. Thus, in addition to the comparison between Δt and Δts, the comparison between the threshold overtime t at which the first time integrated value V exceeds the predetermined speed threshold Vs and the time threshold ts or the second time integrated value V ′ is obtained. It is also possible to employ a method in which the threshold crossing time t'exceeding a predetermined speed threshold Vs and the time threshold ts' are used together.

Further, in the embodiments of FIGS. 1 to 11, the case where two inflators are used has been described, but it goes without saying that the present invention can be similarly applied to the case where three or more inflators are used. . In this case, it is possible to operate only a part of the inflators in the mode of operation of the slow expansion.

Further, the inflator used in the present invention is
In some cases, multiple independent inflators are used, but 1
By defining the inside of one inflator housing into a plurality of independent combustion chambers and disposing an ignition device in each combustion chamber, an inflator that can independently operate each combustion chamber may be used. The plurality of inflators referred to in the present invention include all of these forms, and as long as the inflators have a plurality of independently ignitable gas generating parts, the inflator may or may not be integrated into one. It goes without saying that it can be used in the invention.

[0058]

As described above, according to the present invention, acceleration sensors are installed both in the passenger compartment and in the crash zone, and based on the difference in the characteristics of the acceleration signals detected by both sensors in various collision modes, Whether or not the inflator needs to be actuated is determined by the difference in the characteristics generated by these calculated values, and the inflator actuation mode is determined by the time difference until the time integrated value based on the acceleration signal signals from both acceleration sensors reaches a predetermined level. Since the collision detection method using only the conventional acceleration sensor installed in the vehicle compartment can easily determine the rough road and the soft crash represented by the low-speed collision, which can be difficult to judge. Become. In particular, in the case of rough road or use where deformation does not occur in the crash zone, or in the case of a low-speed collision in which the vehicle body deformation is small, the waveforms of both acceleration sensors are substantially the same, so the difference between the two time integrated values is extremely small. It becomes a value. Therefore, by using this difference in time integration value directly or indirectly to judge whether or not the airbag needs to be operated, the airbag malfunction can be completely eliminated in a soft crash such as a rough road or a low-speed collision with less vehicle deformation. It is possible to prevent it.

The second time integral value V'based on the acceleration signal from the second acceleration sensor installed in the crash zone.
Is greater than the first time integral value V based on the acceleration signal from the first acceleration sensor installed in the vehicle compartment, and becomes a large value in an early period after the collision, and therefore V ′ itself or V ′ and V
By using the difference Vd or the difference amount Gd of this difference and comparing it with the threshold value of the corresponding time function, the detection is delayed in a serious collision such as a high-speed front collision or a high-speed oblique collision and the acceleration sensor in the vehicle interior. Even middle-speed center pole collisions, which tend to occur, can be detected very early after a collision, so the need to deploy the airbag (whether or not the inflator needs to be activated) can be determined at an appropriate timing without worrying about operation delay. It becomes possible to do.

Since a collision can be detected at an extremely early time after the collision, a plurality of inflators are used, and the calculation time for controlling the operating mode of the inflator by providing a timing difference between the inflators is set from the collision detection to the inflator. Since a sufficient time margin can be obtained before the operation timing, it becomes possible to perform a complicated calculation for controlling the inflator operation mode, and it is possible to control the airbag deployment mode to an optimum mode according to the collision mode. It will be easy.

Further, since the threshold value is a function of the first time integral value V, it does not depend on time, so that stable judgment performance can be obtained. It becomes possible to make an airbag deployment judgment system that has both judgment and certain judgment.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an operation control device for an inflator for an airbag device according to the present invention.

FIG. 2 is a block diagram showing another embodiment of the operating mode determination system of the inflator according to the present invention.

FIG. 3 is a block diagram showing another embodiment of the system for determining whether or not to operate the inflator according to the present invention.

FIG. 4 is a block diagram showing still another embodiment of the system for determining whether or not to operate the inflator according to the present invention.

FIG. 5 is a block diagram showing still another embodiment of the operation necessity judgment system of the inflator of the present invention.

FIG. 6 is a block diagram showing still another embodiment of the system for determining whether or not to operate the inflator according to the present invention.

FIG. 7 is a block diagram showing still another embodiment of the system for determining whether or not to operate the inflator according to the present invention.

FIG. 8 is a block diagram showing still another embodiment of the operation necessity determination system for the inflator of the present invention.

FIG. 9 is a block diagram showing still another embodiment of the operation necessity determination system for the inflator of the present invention.

FIG. 10 is a block diagram showing still another embodiment of the operation necessity determination system of the inflator of the present invention.

FIG. 11 is a block diagram showing still another embodiment of the operation necessity determination system for the inflator of the present invention.

FIG. 12 is a diagram showing a temporal change of an integrated value of acceleration values detected by an acceleration sensor in various collision modes, etc., and (A) is a time based on an acceleration value from an acceleration sensor installed in a vehicle interior. FIG. 3B is a diagram showing a change in the integrated value, and FIG. 6B is a diagram showing a change in the time integrated value based on the acceleration value from the acceleration sensor installed in the crash zone.

FIG. 13 is a temporal change of a difference between a time integrated value based on an acceleration value from an acceleration sensor installed in a vehicle interior in various collision modes and a time integrated value based on an acceleration value from an acceleration sensor installed in a crash zone. FIG.

FIG. 14 shows the amount of change in the difference between the time integrated value based on the acceleration value from the acceleration sensor installed in the vehicle interior in various collision modes and the time integrated value based on the acceleration value from the acceleration sensor installed in the crash zone. It is a diagram which shows a time change.

FIG. 15 shows the difference between the time integrated value based on the acceleration value from the acceleration sensor installed in the vehicle interior in various collision modes and the time integrated value based on the acceleration value from the acceleration sensor installed in the crash zone in the vehicle interior. It is a diagram which shows the relationship with the time integral value based on the acceleration value from the installed acceleration sensor.

FIG. 16 is a diagram showing a relationship between a time integration value based on an acceleration value from an acceleration sensor installed in a crash zone and a time integration value based on an acceleration value from an acceleration sensor installed in a vehicle compartment in various collision modes. Is.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 1st acceleration sensor (vehicle interior acceleration sensor) 2 2nd acceleration sensor (crash zone acceleration sensor) 3 Computation circuit 5, 5'offset means 6, 6'integration means 12, 27 Comparator for judging deployment mode of an inflator 15, 24, 28, 34, 44, 46, 48, 52, 56, 58 Comparator 19 for determining whether or not to operate the inflator 19 Reset circuit 20 First inflator trigger circuit 21 Second inflator trigger circuit 22 Airbag V First Time integration value V ′ Second time integration value Vd Difference between time Vd and Vd Gd Vd with time Vs1 First speed threshold Vs2 of time function Second speed threshold Vs3 of function of second time integration V ′ Third speed threshold Vs4 of function of time integrated value V Fourth speed threshold Vs5 of time function of function Fifth speed threshold of function of first time integrated value V

Continuation of the front page (56) Reference JP-A-3-238358 (JP, A) JP-A-4-353053 (JP, A) JP-A-4-244454 (JP, A) JP-A-4-317837 (JP , A) JP 7-76256 (JP, A) JP 7-323803 (JP, A) JP 11-189127 (JP, A) Actual flat 5-65706 (JP, U) Actual flat 3-110966 (JP, U) Actual Kaihei 4-7966 (JP, U) Registered utility model 3032177 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60R 21/32

Claims (24)

(57) [Claims] 1. An airbag device operation, comprising a plurality of inflators for one airbag, and when detecting a collision of a vehicle, controlling the operation of the plurality of inflators according to the degree of the collision. In the control device, a first acceleration sensor (1) installed in a vehicle compartment to constantly detect an acceleration (G) of the installation portion, and an acceleration (G) of the installation portion installed in a front crash zone of the vehicle body. ') 2nd acceleration sensor that constantly detects (2)
The acceleration signal (G) from the first acceleration sensor (1) exceeds a predetermined value (G1), the acceleration sensor (G)
Is started, and the acceleration signal (G ′) from the second acceleration sensor (2) has a predetermined value (G1 ′).
The calculation based on the acceleration sensor (G ′) is started from the time point of exceeding, and the first time integration value (V), which is time-integrated based on the acceleration signal (G) from the first acceleration sensor (1), A second time integration value (V ') time-integrated based on the acceleration signal from the second acceleration sensor (2), and an integration value difference (Vd = V') between the second time integration value and the first integration value. -V) or the amount of change in the difference between them and the integrated value (Gd = d (Vd) / d
Based on the difference in characteristics of various collision modes of t), these are appropriately combined to determine whether or not the plurality of inflators need to be operated, and after the calculation based on the first acceleration sensor (1) is started, The time (t) required for the first time integrated value (V) to exceed a predetermined value (Vs) and the second time integrated value after the calculation based on the second acceleration sensor (2) is started. The difference (Δt) from the time (t ′) required until (V ′) exceeds a predetermined value (Vs) is obtained, and the operating mode of the plurality of inflators is determined based on the magnitude of the time difference (Δt). Inflator actuation control device for an air bag device, characterized in that 2. The operation mode of the inflator is composed of two types, that is, a slow deployment for gently deploying the airbag and a rapid deployment for rapidly deploying the airbag, and the time difference (Δ
t) is less than a predetermined time difference threshold (Δts) (Δt <Δt
The operation control of the inflator for an airbag device according to claim 1, wherein a rapid deployment operation mode is selected in the case of s), and a slow deployment is selected in the case of the threshold value or more (Δt ≧ Δts). apparatus 3. The actuation control device for an inflator for an airbag device according to claim 2, wherein the time difference threshold value (Δts) is a threshold value of a time function. 4. The operation control device for an inflator for an airbag device according to claim 3, wherein the time difference threshold value (Δts) is a threshold value of a time function that decreases with time. 5. The operating mode of the inflator is composed of two types, that is, a slow deployment for gently deploying the airbag and a rapid deployment for rapidly deploying the airbag, and the time difference (Δ
t) is less than a predetermined first time difference threshold (Δts1) and is equal to or greater than the second time difference threshold (Δts2) (Δts2 ≦ Δ
If t <Δts1), select the operation mode of rapid deployment,
The operation control device for an inflator for an air bag device according to claim 1, wherein when the first time difference threshold value or more (Δt ≧ Δts1), slow deployment is selected. 6. The operation mode of the inflator is composed of two types, that is, a slow deployment for gently deploying the airbag and a rapid deployment for rapidly deploying the airbag, and the time difference (Δ
t) is less than a predetermined time difference threshold (Δts) (Δt <Δt
s) and the time (t) required until the first time integrated value (V) exceeds a predetermined value (Vs) after the calculation based on the first acceleration sensor (1) is started. If the time difference is less than a predetermined time threshold value (ts) (t <ts), the operation mode of rapid deployment is selected, and the time difference is equal to or more than a predetermined time difference threshold value (Δt ≧ Δts) or the first time integrated value is 2. The airbag device according to claim 1, wherein when the time (t) required to exceed a predetermined value is equal to or longer than the time threshold value (ts) (t ≧ ts), the slow expansion is selected. Inflator operation control device 7. The operating mode of the inflator is of two types, a slow deployment for gently deploying the airbag and a rapid deployment for rapidly deploying the airbag, and the time difference (Δ
t) is less than a predetermined time difference threshold (Δts) (Δt <Δt
s) and the time (t) required until the second time integral value (V ′) exceeds a predetermined value (Vs ′) after the calculation based on the second acceleration sensor (2) is started. ')
Is less than a predetermined time threshold value (ts') (t '<ts'), the operation mode of rapid expansion is selected, and the time difference is equal to or more than a predetermined time difference threshold value (Δt ≧ Δts) or the second time period. The time (t ′) required until the integrated value exceeds the predetermined value is equal to or longer than the time threshold value (ts ′) (t ′ ≧ t
In the case of s'), the operation control device for the inflator for an airbag device according to claim 1, wherein a slow expansion is selected. 8. The gentle deployment activates only some of the plurality of inflators to gently deploy the airbag, and the rapid deployment shifts all the inflators at the same time or slightly shifts the ignition timing. The airbag system according to any one of claims 2 to 7, wherein the airbag is rapidly deployed by igniting the airbag. 9. The slow deployment deploys the airbag gently by shifting ignition timings of the plurality of inflators, and the rapid deployment ignites all of the plurality of inflators simultaneously to rapidly deploy the airbag. The operation control device for an inflator for an air bag device according to any one of claims 2 to 7, which is adapted to be deployed. 10. The gentle deployment causes the airbag to be gently deployed by increasing the ignition timing difference between the plurality of inflators, and the rapid deployment causes the airbag to expand by reducing the ignition timing difference between the inflators. The operation control device for an inflator for an air bag device according to any one of claims 2 to 7, wherein the bag is adapted to be rapidly deployed. 11. The inflator comprises two, a first inflator and a second inflator.
0. An inflator operation control device for an airbag device according to any one of 0. 12. The first time integral value (V) is compared with a first speed threshold value (Vs1) of a predetermined time function for determining whether or not the inflator needs to be actuated, and the first time integral value is calculated. 12. If the value is equal to or more than the threshold value (V ≧ Vs1), the inflator is operated according to a separately selected operation mode of the inflator, wherein the inflator according to any one of claims 1 to 11 is operated. Control device 13. The first time integral value (V) is compared with a second speed threshold value (Vs2) for determining whether or not the inflator needs to be operated, and the first time integral value is equal to or more than the threshold value (Vs2). When V ≧ Vs2), the inflator is operated according to the operation mode of the inflator selected separately, and the inflator is operated based on the acceleration signal (G ′) from the second acceleration sensor (2). The necessity calculation circuit (25) performs a predetermined calculation to make a primary judgment as to whether or not the inflator needs to be operated, and changes the value of the second speed threshold value (Vs2) based on the judgment result. An inflator operation control device for an airbag device according to any one of claims 1 to 11. 14. The result of the primary judgment as to whether or not the inflator should be operated by the inflator operation necessity calculation circuit (25) based on the acceleration signal (G ′) from the second acceleration sensor (2) indicates that the operation is “necessary”. In this case, the second speed threshold value (V
The value of s2) is changed so as to be relatively lowered, and when it is determined that the operation is "unnecessary", the second speed threshold value (V
14. The operation control device for an inflator for an airbag device according to claim 13, wherein the value of s2) is changed so as to be relatively increased. 15. Comparing the second time integral value (V ′) with a third speed threshold (Vs3) as a function of the first time integral value (V) for determining whether or not the inflator needs to be actuated. However, when the second time integrated value is equal to or more than the threshold value (V ′ ≧ Vs3), the inflator is operated according to the operation mode of the inflator selected separately.
11. An operation control device for an inflator for an airbag device according to any one of 1 to 11. 16. The integrated value difference (Vd) is compared with a predetermined fourth speed threshold value (Vs4) of the time function, and when the integrated value difference is equal to or more than the threshold value (Vd ≧ Vs4), it is selected separately. The operation control device for an inflator for an air bag device according to any one of claims 1 to 11, wherein the inflator is operated according to the operation mode of the inflator. 17. The change amount (Gd) of the integrated value difference is compared with a predetermined difference change threshold value (Gs) of the time function, and when the change amount is equal to or more than the threshold value (Gd ≧ Gs), it is separately calculated. The inflator operation control device for an airbag device according to any one of claims 1 to 11, wherein the inflator is operated according to a selected operation mode of the inflator. 18. The integrated value difference (Vd) is compared with the fourth speed threshold value (Vs4), the change amount (Gd) of the integrated value difference is compared with the difference change threshold value (Gs), and The integrated value difference is not less than the fourth speed threshold value (Vd ≧ Vs4)
And the amount of change in the integrated value difference is greater than or equal to the difference change threshold (G
The inflator is operated according to an operation mode of the inflator which is separately selected when one or both of the conditions d ≧ Gs (t)) are satisfied. Control device for inflator for airbag system 19. The integrated value difference (Vd) is compared with the fourth speed threshold value (Vs4), the change amount (Gd) of the integrated value difference is compared with the difference change threshold value (Gs), and The first time integrated value (V) is compared with the first speed threshold value (Vs1), and the integrated value difference is not less than the fourth speed threshold value (Vd ≧ Vs4).
And the amount of change in the integrated value difference is greater than or equal to the difference change threshold (G
One or both of the conditions d ≧ Gs) are satisfied, and the first time integral value is equal to or more than the first speed threshold (V ≧
In the case of Vs1), the inflator actuation control device according to any one of claims 1 to 11, wherein the inflator is actuated according to the actuation mode of the inflator selected separately. 20. The integrated value difference (Vd) is compared with a predetermined fifth speed threshold value (Vs5) set as a function of the first time integrated value (V), and the integrated value difference is greater than or equal to the threshold value. (V
12. When d ≧ Vs5), the inflator operation control device according to any one of claims 1 to 11, wherein the inflator is operated according to a separately selected operation mode of the inflator. 21. The integrated value difference (Vd) is compared with the fifth speed threshold value (Vs5), the change amount (Gd) of the integrated value difference is compared with the difference change threshold value (Gs), The integrated value difference is not less than the fifth speed threshold value (Vd ≧ Vs5)
And the amount of change in the integrated value difference is greater than or equal to the difference change threshold (G
The airbag device according to any one of claims 1 to 11, wherein when one or both of the conditions (d ≧ Gs) are satisfied, the inflator is operated according to a separately selected operation mode of the inflator. Inflator operation control device 22. The second time integrated value (V ′) is compared with a predetermined third speed threshold value (Vs3) set as a function of the first time integrated value (V), and the integrated value difference is obtained. Amount of change (Gd) is compared with the difference change threshold value (Gs), and the second time integration value is equal to or greater than the third speed threshold value (V ′ ≧ V
s3) and the amount of change in the integrated value difference satisfying one or both of the difference change threshold value or more (Gd ≧ Gs), the inflator is operated according to a separately selected operation mode of the inflator. An inflator operation control device for an airbag device according to any one of claims 1 to 11. 23. A preset predetermined acceleration value (G2) is subtracted from the acceleration value (G) detected by the first acceleration sensor (1), and the subtracted value (G3) is integrated over time. To calculate a first time integrated value (V), subtract a preset predetermined acceleration value (G2 ′) from the acceleration value (G ′) detected by the second acceleration sensor (2), and perform the subtraction. The integrated value (G3 ') is time-integrated to obtain the second time integrated value (V').
The operation control device for an inflator for an airbag device according to any one of claims 1 to 22, wherein 24. The second acceleration sensor (2), and an arithmetic circuit up to a time integration means (6 ') for time component based on the acceleration signal (G') are arranged in the crash zone. Item 23. An inflator operation control device for an airbag device according to any one of items 1 to 23.