JP2001010441A - Occupant crash protection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely expand a detonator in multistage with a simple structure by arranging collision detecting units for outputting signals in the initial stage of a collision and signals after the initial stage in the front end of a vehicle and within a cabin, and developing an air bag stepwise on the basis of the output signal from each unit. SOLUTION: An initial collision detection unit 1 for outputting a collision judgment signal T1 in the initial stage of a collision and a collision judgment signal T2 after the initial stage of the collision is provided on the front end of a vehicle. A collision judgment unit 2 for outputting a collision judgment signal S1 in the initial stage of the collision and a collision judgment signal S32 after the initial stage of the collision is provided within a cabin. The output of an AND gate for determining the logic sum of the collision judgment signals T1, S1 is supplied to a detonator 4 to partially develop an air bag. The output of an AND gate 5 for determining the logic sum of the collision judgment signals T2, S2 is supplied to a detonator 6 to fully develop the air bag.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an occupant protection device for protecting an occupant by gradually deploying an airbag in a collision accident from the front of a vehicle.

An occupant protection system of this kind usually has two primers, and firstly, an airbag deployment current (airbag deployment signal) is applied to the first primer to perform half deployment, and after a lapse of a predetermined time, the other is deactivated. One airbag was fully deployed by further applying an airbag deployment current to the primer.

[0003]

However, in the structure of the occupant protection device as described above, the occupant protection device is automatically turned on after a predetermined time from the supply of the deployment current to the first primer.
Since the deployment current is supplied to the second primer and the airbag is deployed in two stages, there is a problem that the deployment timing of the second airbag may not be optimal. .

[0004] The present invention has been made in view of such problems, and has as its object to simplify the configuration of an occupant protection device that deploys an airbag in two stages.

[0005]

A first invention is arranged at a front end of a vehicle, detects an acceleration signal at a level at an initial stage of a collision, outputs a first collision determination signal, and outputs the first collision determination signal. A first collision detection unit that detects an acceleration signal at a level greater than the level and outputs a second collision determination signal;
A third collision detection signal is output by detecting an acceleration signal at the initial stage of the collision and outputting a third collision determination signal, and a fourth collision signal is detected by detecting an acceleration signal at a higher level than the initial stage. The logical AND of the second collision detection unit that outputs the determination signal and the first and third collision determination signals from each of the first and second collision detection units is output, and the first airbag deployment signal is output. A first AND gate, and a second AND gate that takes the logical product of the second and fourth collision determination signals from the first and second collision detection units and outputs a second airbag deployment signal. Receiving the first airbag deployment signal from the first AND gate to partially deploy the airbag, and receiving the second airbag deployment signal from the second AND gate to fully deploy the airbag. Causing an occupant protection device.

According to a second invention, each of the first and second collision detection units in the first invention detects whether an acceleration signal from an acceleration sensor has exceeded a first reference value,
A trigger / reset circuit for outputting a trigger signal when it is determined that the threshold value has been exceeded, a reference value generating circuit for receiving a trigger signal from the trigger / reset circuit to generate a second reference value, and receiving a trigger signal from the trigger / reset circuit An integration circuit that starts integration of the acceleration signal from the acceleration sensor, a second reference value output from the reference value generation circuit, and an integration output output from the integration circuit are compared. And a comparison circuit that outputs a deployment request signal when the value exceeds two reference values.

According to a third aspect of the present invention, the trigger / reset circuit according to the second aspect of the present invention is configured such that, when it is determined that the acceleration signal from the acceleration sensor has fallen below the first reference value for a predetermined time or more, An occupant protection device characterized by supplying a reset signal to a generation circuit and an integration circuit.

[0008]

Next, an embodiment of the present invention will be described below. Embodiment 1 FIG. In FIG. 1, reference numeral 1 denotes a first collision determination signal T1 (shown in FIG. 2) which is disposed near a front end portion of a vehicle, for example, near a radiator grill, detects an acceleration signal (FIG. 2A) generated in an initial stage of a collision. And outputs an acceleration signal generated at a later stage than the initial stage of the collision to detect a second collision determination signal T2 (the collision may be larger than when the first collision determination signal T1 is output). The first collision detection unit outputs the first collision detection unit (which is output when it is determined that there is a possibility).

Reference numeral 2 denotes a third collision determination signal S1 (shown in FIG. 2) which is disposed on the floor in the interior of the vehicle, for example, near the shift lever, detects an acceleration signal at a level at the initial stage of the collision. A collision detection unit (second collision detection unit) that detects an acceleration signal generated in a subsequent stage and outputs a fourth collision determination signal S2 (shown in FIG. 2). Although it has almost the same circuit configuration as the collision detection unit 1, the only difference is that the circuit characteristics of the individual circuit blocks are different.
Hereinafter, only the collision determination unit 2 will be described in detail, and the detailed description of the initial collision determination unit 1 will be omitted.

Reference numeral 3 denotes first and third output signals from the initial collision detection unit 1 and the collision judgment unit 2, respectively.
The first AND gate that takes the logical product of the collision determination signals T1 and S1 and outputs the first airbag deployment signal,
The first airbag deployment signal from AND Gate 3
The airbag is supplied to one of the primers 4 of an inflator (not shown) having the two primers 4 and 6 so that the airbag is semi-deployed.

Reference numeral 5 denotes second and fourth signals output from the initial collision detection unit 1 and the collision judgment unit 2, respectively.
The second AND gate 5, which takes the logical product of the collision determination signals T2 and S2 and outputs the second airbag deployment signal, outputs the second airbag deployment signal from the second AND gate 5 to the other of the inflators. And the airbag in a semi-deployed state is fully deployed.

The general operation of the overall configuration of the apparatus will be described as follows with reference to FIG. That is, when a collision occurs from the front of the vehicle, the vehicle is gradually destroyed from the front end. As a result, for example, as shown in FIG. 2A, the magnitude of the acceleration signal gradually increases. Therefore, the magnitude of the collision is determined based on the level of the magnitude of the acceleration signal. for that reason,
At time t1 when the magnitude exceeds the level L1, the initial collision detection unit 1 first sets the output terminal T1 to the high level and outputs the first collision determination signal T1, and thereafter, the magnitude of the acceleration signal exceeds the level L3. At time t3, the output terminal T2 is set to the high level to output the second collision determination signal T2.

On the other hand, the collision determination unit 2 determines the magnitude of the collision based on the level of the magnitude of the acceleration signal transmitted near the shift lever arranged beside the driver's seat. As a result, the magnitude of the acceleration signal becomes level L
2 and L4, respectively, at times t2 and t4, at time t2 (between times t1 and t3), the output terminal S1 is set to the high level to output the third collision determination signal S1, and thereafter, at time t4 (time t3 After that, the output terminal S2 is set to the high level to output the fourth collision determination signal S2.

Thus, the first AND gate 3 has the first
When the third collision determination signals T1 and S1 are supplied, the first primer 4 is ignited (time t2), and the airbag is half-deployed. While the airbag is half-deployed in this manner, the second and fourth collision determination signals T
When S2 is supplied, the second primer 6 is ignited (time t4), and the airbag is fully deployed in two stages.

Next, the detailed configuration of the collision judging unit 2 will be described below with reference to FIG. Reference numeral 20 denotes a second acceleration sensor that detects an acceleration signal generated in the vehicle front-rear direction at the time of a vehicle collision. The acceleration signal output from the second acceleration sensor 20 is supplied to a second digital high-pass filter 21 and is supplied to a second digital high-pass filter 21. A frequency component is extracted from the acceleration signal and output. Further, the extracted acceleration signal is supplied to a second digital low-pass filter 22. The second digital low-pass filter 22 receives the acceleration signal from the second digital high-pass filter 21 and receives a signal having a frequency lower than a predetermined frequency. The acceleration signal of the component (see reference symbol A in FIG. 5A)
(3) supply to the second integration circuit 24;

The second trigger / reset circuit 23 receives the acceleration signal A output from the second digital low-pass filter 22, and changes the magnitude of the acceleration signal A from a small value to a large value to thereby determine a predetermined value. The value V1 (FIG. 5)
(A) is output as a trigger signal (rising edge of FIG. 5B) which is latched when the threshold value is exceeded for the first time. Fourth threshold generation circuit 27 and second integration circuit 2
4 are output in parallel.

A reset signal (falling edge of FIG. 5 (B)) is generated as a third threshold value when the voltage falls below a predetermined value V1 while changing from a large value to a small value and the state continues for a predetermined time T1 or more. The signals are output to the circuit 25, the fourth threshold value generating circuit 27, and the second integrating circuit 24 in parallel.

When the trigger signal is supplied from the trigger / reset circuit 25, the third threshold value generating circuit 25 synchronizes with the trigger signal as shown by reference numeral C2 in FIG.
The value changes with the elapse of time, that is, a constant value L1 for the first predetermined time, and thereafter, the value linearly increases in a clamp shape for the predetermined time, and then the constant value L
A first threshold value that becomes 2 is output.

Similarly to the third threshold value generating circuit 25, when the trigger signal is supplied, the fourth threshold value generating circuit 27 synchronizes with the trigger signal as indicated by reference numeral C3 in FIG. A second threshold value that changes with time, that is, a constant value L2 for the first predetermined time, then increases in a clamped manner for a predetermined time, and thereafter becomes a constant value L3. Output the value. The voltage value of the second threshold value is set to be higher than that of the first threshold value.

When the trigger signal is supplied from the trigger / reset circuit 35, the second integration circuit 24 synchronizes with the acceleration signal supplied from the second digital low-pass filter 22 (symbol shown in FIG. 5A). A (indicated by A) is added and integrated to convert it into a speed signal (indicated by C1 in FIG. 5C).

Reference numeral 26 denotes a third comparison circuit, which is a speed signal C1 supplied from the second integration circuit 24 based on the first threshold value C2 supplied from the third threshold value creation circuit 25.
When the speed signal C1 exceeds the first threshold value C2, the output is kept at a high level (the first collision determination signal) until the speed signal C1 is reset by the reset signal from the second trigger / reset circuit 35. S1) (FIG. 5)
(D)).

Reference numeral 28 denotes a fourth comparison circuit, which is a speed signal C1 supplied from the second integration circuit 24 with reference to the second threshold value C3 supplied from the fourth threshold value creation circuit 27.
When the speed signal C1 exceeds the second threshold value C3, the output is maintained at a high level (the second collision determination signal S2) until the speed signal C1 is reset as in the previous period (FIG. 5). (E)).

Next, the operation of the above configuration will be described. Along with the collision, the second acceleration sensor 20 indicates a symbol A2 in FIG.
When the acceleration signal A2 as shown by is output, the second
The signal is supplied to a second trigger / reset circuit 23 and a second integration circuit 24 via a high-pass filter 21 and a second low-pass filter 22 in series.

The second trigger / reset circuit 23 outputs the acceleration signal A supplied from the second low-pass filter 22 to the first
When the threshold value V1 is exceeded, the third threshold value generation circuit 25,
The operation is started by triggering each of the fourth threshold value generating circuit 27 and the second integrating circuit 24.

As a result, the third comparison circuit 26 outputs the third
The first threshold value C2 from the threshold value generation circuit 25 is compared with the speed signal C1 from the second integration circuit 24 (FIG. 5).
(C) and C2), the speed signal C
When 1 exceeds the first threshold value C2, the output S1 is maintained at a high level (see FIG. 5D).

The fourth comparison circuit 28 compares the speed signal C1 from the second integration circuit 24 with reference to the second threshold value C3 from the fourth threshold value generation circuit 27 (FIG. 5). (C) are indicated by reference numerals C1 and C3), when the speed signal C1 exceeds the second threshold value C3, the output S2
Is maintained at a high level (see FIG. 5E).

Next, the detailed configuration of the initial collision judging unit 1 will be described with reference to FIG. 4. Since the configuration of this unit 1 is basically the same as that of the collision judging unit 2 explained in FIG. Detailed description is omitted.

In FIG. 4, the first acceleration sensor 1
0 corresponds to the second acceleration sensor 20 in FIG. 3, and an acceleration signal (FIG. 2) shown in FIG.
(Greater than that shown in (A2)). The first digital high-pass filter 11 is provided to the second digital high-pass filter 21, the first digital low-pass filter 12 is provided to the second digital low-pass filter 22, the first trigger / reset circuit 13 is provided to the second trigger / reset circuit 23, and the first The integrating circuit 14 is connected to the second integrating circuit 24, the first threshold value generating circuit 15 is connected to the second threshold value generating circuit 25, the second threshold value generating circuit 17 is connected to the fourth threshold value generating circuit 27, The first comparing circuit 16 corresponds to the third comparing circuit 26, and the second comparing circuit 18 corresponds to the fourth comparing circuit 28. At the time t1 when the acceleration signal L1 is exceeded, the output terminal T1 goes high and the level exceeds the level L3. At time t3, the output terminal T2 is set to the high level.

As a result, the first AND gate 3 takes the logical product of the outputs of the first and third comparison circuits 16 and 26,
When a high level signal is supplied from both sides, the output is maintained at a high level (first deployment instruction signal), a deployment current is supplied to the first primer 4 and the airbag is deployed halfway.

The second AND gate 5 calculates the logical product of the outputs from the second comparison circuit 18 and the fourth comparison circuit 28, and when a high level signal is supplied from both, the output of the second AND gate 5 becomes high (second level). (Deployment instruction signal), and supply a deployment current to the second primer 6 to fully deploy the airbag.

[0031]

As described above, according to the first aspect of the present invention, there is an effect that a device that can be deployed in multiple stages with a simple structure and with high accuracy can be obtained.

According to the second aspect, the accuracy of the deployment judgment of the second primer can be improved, and there is an effect that the deployment current is not supplied to the second primer when unnecessary.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram for describing an overall schematic configuration of a first embodiment according to the present invention.

FIG. 2 is an explanatory waveform diagram for explaining the operation of FIG. 1;

FIG. 3 is an explanatory diagram of a circuit block of a collision determination unit 2 in FIG. 1;

FIG. 4 is a circuit block diagram of the initial collision detection unit 1 in FIG.

FIG. 5 is an explanatory waveform diagram for explaining the operation of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Initial collision detection unit (1st collision detection unit) 2 Collision judgment unit (2nd collision detection unit) 3,5 AND gate 4,6 Primer 10,20 Acceleration sensor 11,21 Digital high-pass filter 12,22 Digital low-pass filter 13 , 23 Trigger / reset circuit 14, 24 Integrator 27 Threshold generator 28 Comparison circuit

Claims (3)

[Claims] 1. An acceleration signal at a front end of a vehicle, which detects an acceleration signal at an initial stage of a collision and outputs a first collision determination signal, and detects an acceleration signal at a later level than the initial stage. A first collision detection unit that outputs a second collision determination signal and outputs a third collision determination signal by detecting an acceleration signal at a level at an initial stage of the collision, which is disposed on the vehicle interior side; A second collision detection unit that detects an acceleration signal at a higher level than the initial stage and outputs a fourth collision determination signal; and first and third collision determination signals from the first and second collision detection units, respectively. AND of the first AND gate that outputs the first airbag deployment signal, and AND of the second and fourth collision determination signals from the first and second collision detection units, respectively, 2nd A second AND gate for outputting a second airbag deployment signal; receiving a first airbag deployment signal from the first AND gate to half-deploy the airbag; and providing a second AND gate from the second AND gate. An occupant protection device that fully deploys the airbag in response to the airbag deployment signal. Each of the first and second collision detection units detects whether an acceleration signal from an acceleration sensor has exceeded a first reference value, and outputs a trigger signal when it is determined that the acceleration signal has exceeded a first reference value. A reset circuit, a reference value generating circuit for receiving a trigger signal from the trigger / reset circuit to generate a second reference value, and starting integration of an acceleration signal from the acceleration sensor upon receiving a trigger signal from the trigger / reset circuit Comparing the second reference value output from the reference value generation circuit with the integration output output from the integration circuit, and outputting a deployment request signal when the integration output exceeds the second reference value. 2. The occupant protection device according to claim 1, further comprising: 3. The trigger / reset circuit resets the reference value generation circuit and the integration circuit when it determines that the acceleration signal from the acceleration sensor is lower than the first reference value for a predetermined time or more. 3. The occupant protection device according to claim 2, wherein a signal is supplied.